Windows stack to heap crash since LLVM update

[SeanTAllen]

This was a corral nightly breakage check on Windows.

2026-03-06T00:41:41.2298337Z Current runner version: '2.332.0'
2026-03-06T00:41:41.2331331Z ##[group]Runner Image Provisioner
2026-03-06T00:41:41.2332426Z Hosted Compute Agent
2026-03-06T00:41:41.2333315Z Version: 20260213.493
2026-03-06T00:41:41.2334272Z Commit: 5c115507f6dd24b8de37d8bbe0bb4509d0cc0fa3
2026-03-06T00:41:41.2335301Z Build Date: 2026-02-13T00:28:41Z
2026-03-06T00:41:41.2336360Z Worker ID: {e426925a-25dc-4209-82b4-842712061ce5}
2026-03-06T00:41:41.2337783Z Azure Region: northcentralus
2026-03-06T00:41:41.2338725Z ##[endgroup]
2026-03-06T00:41:41.2340731Z ##[group]Operating System
2026-03-06T00:41:41.2341675Z Microsoft Windows Server 2025
2026-03-06T00:41:41.2342585Z 10.0.26100
2026-03-06T00:41:41.2343276Z Datacenter
2026-03-06T00:41:41.2344032Z ##[endgroup]
2026-03-06T00:41:41.2344804Z ##[group]Runner Image
2026-03-06T00:41:41.2345612Z Image: windows-2025
2026-03-06T00:41:41.2346430Z Version: 20260302.43.1
2026-03-06T00:41:41.2348731Z Included Software: https://github.com/actions/runner-images/blob/win25/20260302.43/images/windows/Windows2025-Readme.md
2026-03-06T00:41:41.2351373Z Image Release: https://github.com/actions/runner-images/releases/tag/win25%2F20260302.43
2026-03-06T00:41:41.2352998Z ##[endgroup]
2026-03-06T00:41:41.2354673Z ##[group]GITHUB_TOKEN Permissions
2026-03-06T00:41:41.2357098Z Metadata: read
2026-03-06T00:41:41.2358339Z Packages: read
2026-03-06T00:41:41.2359088Z ##[endgroup]
2026-03-06T00:41:41.2361791Z Secret source: Actions
2026-03-06T00:41:41.2362938Z Prepare workflow directory
2026-03-06T00:41:41.2762769Z Prepare all required actions
2026-03-06T00:41:41.2800821Z Getting action download info
2026-03-06T00:41:41.5314991Z Download action repository 'actions/checkout@v4.1.1' (SHA:b4ffde65f46336ab88eb53be808477a3936bae11)
2026-03-06T00:41:41.6589750Z Download action repository 'zulip/github-actions-zulip@e4c8f27c732ba9bd98ac6be0583096dea82feea5' (SHA:e4c8f27c732ba9bd98ac6be0583096dea82feea5)
2026-03-06T00:41:42.4888905Z Complete job name: Verify main against the latest ponyc on Windows
2026-03-06T00:41:42.6151304Z ##[group]Run actions/checkout@v4.1.1
2026-03-06T00:41:42.6152363Z with:
2026-03-06T00:41:42.6152776Z repository: ponylang/corral
2026-03-06T00:41:42.6153446Z token: ***
2026-03-06T00:41:42.6153829Z ssh-strict: true
2026-03-06T00:41:42.6154257Z persist-credentials: true
2026-03-06T00:41:42.6154717Z clean: true
2026-03-06T00:41:42.6155118Z sparse-checkout-cone-mode: true
2026-03-06T00:41:42.6155606Z fetch-depth: 1
2026-03-06T00:41:42.6156012Z fetch-tags: false
2026-03-06T00:41:42.6156417Z show-progress: true
2026-03-06T00:41:42.6156825Z lfs: false
2026-03-06T00:41:42.6157196Z submodules: false
2026-03-06T00:41:42.6157615Z set-safe-directory: true
2026-03-06T00:41:42.6158297Z ##[endgroup]
2026-03-06T00:41:42.7531999Z Syncing repository: ponylang/corral
2026-03-06T00:41:42.7533785Z ##[group]Getting Git version info
2026-03-06T00:41:42.7534409Z Working directory is 'D:\a\corral\corral'
2026-03-06T00:41:42.8451588Z [command]"C:\Program Files\Git\bin\git.exe" version
2026-03-06T00:41:43.0512820Z git version 2.53.0.windows.1
2026-03-06T00:41:43.0587422Z ##[endgroup]
2026-03-06T00:41:43.0613291Z Temporarily overriding HOME='D:\a_temp\d071f7c2-a49b-45aa-baab-d3f2fce23675' before making global git config changes
2026-03-06T00:41:43.0616770Z Adding repository directory to the temporary git global config as a safe directory
2026-03-06T00:41:43.0623938Z [command]"C:\Program Files\Git\bin\git.exe" config --global --add safe.directory D:\a\corral\corral
2026-03-06T00:41:43.0953509Z Deleting the contents of 'D:\a\corral\corral'
2026-03-06T00:41:43.0961156Z ##[group]Initializing the repository
2026-03-06T00:41:43.0969280Z [command]"C:\Program Files\Git\bin\git.exe" init D:\a\corral\corral
2026-03-06T00:41:43.1459221Z Initialized empty Git repository in D:/a/corral/corral/.git/
2026-03-06T00:41:43.1511186Z [command]"C:\Program Files\Git\bin\git.exe" remote add origin https://github.com/ponylang/corral
2026-03-06T00:41:43.1932271Z ##[endgroup]
2026-03-06T00:41:43.1935425Z ##[group]Disabling automatic garbage collection
2026-03-06T00:41:43.1936198Z [command]"C:\Program Files\Git\bin\git.exe" config --local gc.auto 0
2026-03-06T00:41:43.2317378Z ##[endgroup]
2026-03-06T00:41:43.2318066Z ##[group]Setting up auth
2026-03-06T00:41:43.2334981Z [command]"C:\Program Files\Git\bin\git.exe" config --local --name-only --get-regexp core.sshCommand
2026-03-06T00:41:43.2787209Z [command]"C:\Program Files\Git\bin\git.exe" submodule foreach --recursive "sh -c "git config --local --name-only --get-regexp 'core.sshCommand' && git config --local --unset-all 'core.sshCommand' || :""
2026-03-06T00:41:44.2986414Z [command]"C:\Program Files\Git\bin\git.exe" config --local --name-only --get-regexp http.https://github.com/.extraheader
2026-03-06T00:41:44.3333048Z [command]"C:\Program Files\Git\bin\git.exe" submodule foreach --recursive "sh -c "git config --local --name-only --get-regexp 'http.https://github.com/.extraheader' && git config --local --unset-all 'http.https://github.com/.extraheader' || :""
2026-03-06T00:41:44.9075688Z [command]"C:\Program Files\Git\bin\git.exe" config --local http.https://github.com/.extraheader "AUTHORIZATION: basic ***"
2026-03-06T00:41:44.9413596Z ##[endgroup]
2026-03-06T00:41:44.9414404Z ##[group]Fetching the repository
2026-03-06T00:41:44.9426890Z [command]"C:\Program Files\Git\bin\git.exe" -c protocol.version=2 fetch --no-tags --prune --no-recurse-submodules --depth=1 origin +1c22097579d4b52b774f54fcc73f87da6b075e2d:refs/remotes/origin/main
2026-03-06T00:41:45.6037465Z From https://github.com/ponylang/corral
2026-03-06T00:41:45.6038607Z * [new ref] 1c22097579d4b52b774f54fcc73f87da6b075e2d -> origin/main
2026-03-06T00:41:45.6292536Z ##[endgroup]
2026-03-06T00:41:45.6293230Z ##[group]Determining the checkout info
2026-03-06T00:41:45.6295671Z ##[endgroup]
2026-03-06T00:41:45.6296783Z ##[group]Checking out the ref
2026-03-06T00:41:45.6308764Z [command]"C:\Program Files\Git\bin\git.exe" checkout --progress --force -B main refs/remotes/origin/main
2026-03-06T00:41:45.7265706Z Switched to a new branch 'main'
2026-03-06T00:41:45.7289499Z branch 'main' set up to track 'origin/main'.
2026-03-06T00:41:45.7345044Z ##[endgroup]
2026-03-06T00:41:45.7765709Z [command]"C:\Program Files\Git\bin\git.exe" log -1 --format='%H'
2026-03-06T00:41:45.8066788Z '1c22097579d4b52b774f54fcc73f87da6b075e2d'
2026-03-06T00:41:45.8583811Z ##[group]Run Invoke-WebRequest https://dl.cloudsmith.io/public/ponylang/nightlies/raw/versions/latest/ponyc-x86-64-pc-windows-msvc.zip -OutFile C:\ponyc.zip;
2026-03-06T00:41:45.8586106Z �[36;1mInvoke-WebRequest https://dl.cloudsmith.io/public/ponylang/nightlies/raw/versions/latest/ponyc-x86-64-pc-windows-msvc.zip -OutFile C:\ponyc.zip;�[0m
2026-03-06T00:41:45.8587562Z �[36;1mExpand-Archive -Path C:\ponyc.zip -DestinationPath C:\ponyc;�[0m
2026-03-06T00:41:45.8588449Z �[36;1m$env:PATH = 'C:\ponyc\bin;' + $env:PATH;�[0m
2026-03-06T00:41:45.8588987Z �[36;1m.\make.ps1 -Command unit-tests 2>&1�[0m
2026-03-06T00:41:45.8792579Z shell: C:\Program Files\PowerShell\7\pwsh.EXE -command ". '{0}'"
2026-03-06T00:41:45.8793447Z ##[endgroup]
2026-03-06T00:42:02.0990623Z fatal: Needed a single revision
2026-03-06T00:42:02.1157708Z Configuration: Release
2026-03-06T00:42:02.1161664Z Version: 0.9.2-
2026-03-06T00:42:02.1164036Z Root directory: D:\a\corral\corral
2026-03-06T00:42:02.1167113Z Source directory: D:\a\corral\corral\corral
2026-03-06T00:42:02.1170167Z Build directory: D:\a\corral\corral\build\release
2026-03-06T00:42:02.1552332Z D:\a\corral\corral\corral\version.pony.in -> D:\a\corral\corral\corral\version.pony
2026-03-06T00:42:02.2521920Z Building builtin -> C:\ponyc\packages\builtin
2026-03-06T00:42:02.3148808Z Building -> C:\ponyc\bin
2026-03-06T00:42:02.3184678Z Building builtin -> C:\ponyc\packages\builtin
2026-03-06T00:42:02.3780855Z Building D:\a\corral\corral\corral -> D:\a\corral\corral\corral
2026-03-06T00:42:02.3887344Z Building cli -> C:\ponyc\packages\cli
2026-03-06T00:42:02.4124750Z Building collections -> C:\ponyc\packages\collections
2026-03-06T00:42:02.4615463Z Building pony_test -> C:\ponyc\packages\pony_test
2026-03-06T00:42:02.4722634Z Building time -> C:\ponyc\packages\time
2026-03-06T00:42:02.4852559Z Building random -> C:\ponyc\packages\random
2026-03-06T00:42:02.5215872Z Building collections/persistent -> C:\ponyc\packages\collections\persistent
2026-03-06T00:42:02.5571331Z Building buffered -> C:\ponyc\packages\buffered
2026-03-06T00:42:02.5770985Z Building cmd -> D:\a\corral\corral\corral\cmd
2026-03-06T00:42:02.5915443Z Building ../logger -> D:\a\corral\corral\corral\logger
2026-03-06T00:42:02.5949509Z Building promises -> C:\ponyc\packages\promises
2026-03-06T00:42:02.6036834Z Building process -> C:\ponyc\packages\process
2026-03-06T00:42:02.6294640Z Building backpressure -> C:\ponyc\packages\backpressure
2026-03-06T00:42:02.6307978Z Building files -> C:\ponyc\packages\files
2026-03-06T00:42:02.6745805Z Building term -> C:\ponyc\packages\term
2026-03-06T00:42:02.6865899Z Building strings -> C:\ponyc\packages\strings
2026-03-06T00:42:02.6895763Z Building signals -> C:\ponyc\packages\signals
2026-03-06T00:42:02.6987298Z Building capsicum -> C:\ponyc\packages\capsicum
2026-03-06T00:42:02.7083371Z Building itertools -> C:\ponyc\packages\itertools
2026-03-06T00:42:02.7413381Z Building ../bundle -> D:\a\corral\corral\corral\bundle
2026-03-06T00:42:02.7533746Z Building ../json -> D:\a\corral\corral\corral\json
2026-03-06T00:42:02.7712403Z Building format -> C:\ponyc\packages\format
2026-03-06T00:42:02.7874914Z Building ../semver/utils -> D:\a\corral\corral\corral\semver\utils
2026-03-06T00:42:02.7915708Z Building ../util -> D:\a\corral\corral\corral\util
2026-03-06T00:42:02.7963501Z Building ../vcs -> D:\a\corral\corral\corral\vcs
2026-03-06T00:42:02.8018589Z Building debug -> C:\ponyc\packages\debug
2026-03-06T00:42:02.8062999Z Building ../semver/range -> D:\a\corral\corral\corral\semver\range
2026-03-06T00:42:02.8084298Z Building ../version -> D:\a\corral\corral\corral\semver\version
2026-03-06T00:42:02.8139653Z Building ../semver/solver -> D:\a\corral\corral\corral\semver\solver
2026-03-06T00:42:02.8234751Z Building ../archive -> D:\a\corral\corral\corral\archive
2026-03-06T00:42:02.8257583Z Building ../mort -> D:\a\corral\corral\corral\mort
2026-03-06T00:42:07.3410594Z Generating
2026-03-06T00:42:07.3467726Z Reachability
2026-03-06T00:42:08.2979588Z Selector painting
2026-03-06T00:42:08.3026895Z Data prototypes
2026-03-06T00:42:08.3107395Z Data types
2026-03-06T00:42:08.3113497Z Function prototypes
2026-03-06T00:42:08.3371668Z Functions
2026-03-06T00:42:08.7265692Z Descriptors
2026-03-06T00:42:14.9009727Z Verifying
2026-03-06T00:42:14.9569798Z Writing D:\a\corral\corral\build\release\corral.obj
2026-03-06T00:42:21.3891384Z Linking D:\a\corral\corral\build\release\corral.exe
2026-03-06T00:42:22.3569275Z Creating library D:\a\corral\corral\build\release\corral.lib and object D:\a\corral\corral\build\release\corral.exp
2026-03-06T00:42:23.7114792Z Error:
2026-03-06T00:42:23.7115248Z no source files in package ''
2026-03-06T00:42:23.8169746Z Building builtin -> C:\ponyc\packages\builtin
2026-03-06T00:42:23.8773408Z Building -> C:\ponyc\bin
2026-03-06T00:42:23.8810445Z Building builtin -> C:\ponyc\packages\builtin
2026-03-06T00:42:23.9372770Z Building D:\a\corral\corral\corral\test -> D:\a\corral\corral\corral\test
2026-03-06T00:42:23.9482040Z Building cli -> C:\ponyc\packages\cli
2026-03-06T00:42:23.9730325Z Building collections -> C:\ponyc\packages\collections
2026-03-06T00:42:24.0185914Z Building pony_test -> C:\ponyc\packages\pony_test
2026-03-06T00:42:24.0298649Z Building time -> C:\ponyc\packages\time
2026-03-06T00:42:24.0444292Z Building random -> C:\ponyc\packages\random
2026-03-06T00:42:24.0840305Z Building collections/persistent -> C:\ponyc\packages\collections\persistent
2026-03-06T00:42:24.1220578Z Building buffered -> C:\ponyc\packages\buffered
2026-03-06T00:42:24.1424671Z Building files -> C:\ponyc\packages\files
2026-03-06T00:42:24.1885939Z Building term -> C:\ponyc\packages\term
2026-03-06T00:42:24.1982527Z Building promises -> C:\ponyc\packages\promises
2026-03-06T00:42:24.2078875Z Building strings -> C:\ponyc\packages\strings
2026-03-06T00:42:24.2108156Z Building signals -> C:\ponyc\packages\signals
2026-03-06T00:42:24.2189399Z Building capsicum -> C:\ponyc\packages\capsicum
2026-03-06T00:42:24.2256186Z Building ../util -> D:\a\corral\corral\corral\util
2026-03-06T00:42:24.2290674Z Building ../logger -> D:\a\corral\corral\corral\logger
2026-03-06T00:42:24.2333084Z Building backpressure -> C:\ponyc\packages\backpressure
2026-03-06T00:42:24.2346141Z Building process -> C:\ponyc\packages\process
2026-03-06T00:42:24.2605374Z Building itertools -> C:\ponyc\packages\itertools
2026-03-06T00:42:24.2839529Z Building ../vcs -> D:\a\corral\corral\corral\vcs
2026-03-06T00:42:24.2890093Z Building debug -> C:\ponyc\packages\debug
2026-03-06T00:42:24.2939686Z Building ../bundle -> D:\a\corral\corral\corral\bundle
2026-03-06T00:42:24.3019080Z Building ../json -> D:\a\corral\corral\corral\json
2026-03-06T00:42:24.3204194Z Building format -> C:\ponyc\packages\format
2026-03-06T00:42:24.3382166Z Building ../semver/utils -> D:\a\corral\corral\corral\semver\utils
2026-03-06T00:42:24.3432732Z Building integration -> D:\a\corral\corral\corral\test\integration
2026-03-06T00:42:24.3529313Z Building ../.. -> D:\a\corral\corral\corral
2026-03-06T00:42:24.3556325Z Building cmd -> D:\a\corral\corral\corral\cmd
2026-03-06T00:42:24.3719019Z Building ../semver/range -> D:\a\corral\corral\corral\semver\range
2026-03-06T00:42:24.3741983Z Building ../version -> D:\a\corral\corral\corral\semver\version
2026-03-06T00:42:24.3806911Z Building ../semver/solver -> D:\a\corral\corral\corral\semver\solver
2026-03-06T00:42:24.3898803Z Building ../archive -> D:\a\corral\corral\corral\archive
2026-03-06T00:42:24.3920919Z Building ../mort -> D:\a\corral\corral\corral\mort
2026-03-06T00:42:28.3032879Z Generating
2026-03-06T00:42:28.3081701Z Reachability
2026-03-06T00:42:29.0792068Z Selector painting
2026-03-06T00:42:29.0834062Z Data prototypes
2026-03-06T00:42:29.0905239Z Data types
2026-03-06T00:42:29.0911568Z Function prototypes
2026-03-06T00:42:29.1158487Z Functions
2026-03-06T00:42:29.4390643Z Descriptors
2026-03-06T00:42:33.5315694Z PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace.
2026-03-06T00:42:33.5316613Z Stack dump:
2026-03-06T00:42:33.5335892Z 0. Running pass "require,function(invalidate),require,cgscc(devirt<4>(InlinerPass,PostOrderFunctionAttrsPass,ArgumentPromotionPass,OpenMPOptCGSCCPass,function<eager-inv;no-rerun>(SROAPass,EarlyCSEPass,SpeculativeExecutionPass,JumpThreadingPass,CorrelatedValuePropagationPass,SimplifyCFGPass<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,InstCombinePass<max-iterations=1;no-verify-fixpoint>,AggressiveInstCombinePass,LibCallsShrinkWrapPass,HeapToStack,TailCallElimPass,SimplifyCFGPass<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,ReassociatePass,ConstraintEliminationPass,loop-mssa(LoopInstSimplifyPass,LoopSimplifyCFGPass,LICMPass,LoopRotatePass<header-duplication;no-prepare-for-lto>,LICMPass,SimpleLoopUnswitchPass<nontrivial;trivial>),SimplifyCFGPass<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,InstCombinePass<max-iterations=1;no-verify-fixpoint>,loop(LoopIdiomRecognizePass,IndVarSimplifyPass,ExtraLoopPassManager,LoopDeletionPass,LoopFullUnrollPass),SROAPass,VectorCombinePass,MergedLoadStoreMotionPass,GVNPass<>,SCCPPass,BDCEPass,InstCombinePass<max-iterations=1;no-verify-fixpoint>,HeapToStack,JumpThreadingPass,CorrelatedValuePropagationPass,ADCEPass,MemCpyOptPass,DSEPass,MoveAutoInitPass,loop-mssa(LICMPass),CoroElidePass,DispatchPonyCtx,MergeMessageSend,SimplifyCFGPass<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,InstCombinePass<max-iterations=1;no-verify-fixpoint>,HeapToStack),PostOrderFunctionAttrsPass,function(require),CoroSplitPass,CoroAnnotationElidePass)),function(invalidate),cgscc(devirt<4>())" on module "test"
2026-03-06T00:42:33.5358004Z 1. Running pass "cgscc(devirt<4>(InlinerPass,PostOrderFunctionAttrsPass,ArgumentPromotionPass,OpenMPOptCGSCCPass,function<eager-inv;no-rerun>(SROAPass,EarlyCSEPass,SpeculativeExecutionPass,JumpThreadingPass,CorrelatedValuePropagationPass,SimplifyCFGPass<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,InstCombinePass<max-iterations=1;no-verify-fixpoint>,AggressiveInstCombinePass,LibCallsShrinkWrapPass,HeapToStack,TailCallElimPass,SimplifyCFGPass<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,ReassociatePass,ConstraintEliminationPass,loop-mssa(LoopInstSimplifyPass,LoopSimplifyCFGPass,LICMPass,LoopRotatePass<header-duplication;no-prepare-for-lto>,LICMPass,SimpleLoopUnswitchPass<nontrivial;trivial>),SimplifyCFGPass<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,InstCombinePass<max-iterations=1;no-verify-fixpoint>,loop(LoopIdiomRecognizePass,IndVarSimplifyPass,ExtraLoopPassManager,LoopDeletionPass,LoopFullUnrollPass),SROAPass,VectorCombinePass,MergedLoadStoreMotionPass,GVNPass<>,SCCPPass,BDCEPass,InstCombinePass<max-iterations=1;no-verify-fixpoint>,HeapToStack,JumpThreadingPass,CorrelatedValuePropagationPass,ADCEPass,MemCpyOptPass,DSEPass,MoveAutoInitPass,loop-mssa(LICMPass),CoroElidePass,DispatchPonyCtx,MergeMessageSend,SimplifyCFGPass<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-lookup;keep-loops;hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,InstCombinePass<max-iterations=1;no-verify-fixpoint>,HeapToStack),PostOrderFunctionAttrsPass,function(require),CoroSplitPass,CoroAnnotationElidePass))" on module "test"
2026-03-06T00:42:33.5368689Z 2. Running pass "HeapToStack" on function "TestGitParseTags_ref_apply_oo"
2026-03-06T00:42:33.5369054Z Exception Code: 0xC0000005
2026-03-06T00:42:33.6500811Z #0 0x00007ff66fa9e0d4 pony_actor_stats (C:\ponyc\bin\ponyc.exe+0x14e0d4)
2026-03-06T00:42:33.6502140Z #1 0x00007ff66fa9da6e pony_actor_stats (C:\ponyc\bin\ponyc.exe+0x14da6e)
2026-03-06T00:42:33.6504451Z #2 0x00007ff66fb80422 pony_asio_event_set_writeable (C:\ponyc\bin\ponyc.exe+0x230422)
2026-03-06T00:42:33.6505333Z #3 0x00007ff670201482 pony_asio_event_set_writeable (C:\ponyc\bin\ponyc.exe+0x8b1482)
2026-03-06T00:42:33.6506124Z #4 0x00007ff6714f951d pony_asio_event_set_writeable (C:\ponyc\bin\ponyc.exe+0x1ba951d)
2026-03-06T00:42:33.6506926Z #5 0x00007ff6702021d6 pony_asio_event_set_writeable (C:\ponyc\bin\ponyc.exe+0x8b21d6)
2026-03-06T00:42:33.6507717Z #6 0x00007ff6714f9005 pony_asio_event_set_writeable (C:\ponyc\bin\ponyc.exe+0x1ba9005)
2026-03-06T00:42:33.6508483Z #7 0x00007ff67066bd56 pony_asio_event_set_writeable (C:\ponyc\bin\ponyc.exe+0xd1bd56)
2026-03-06T00:42:33.6509265Z #8 0x00007ff6714f9a38 pony_asio_event_set_writeable (C:\ponyc\bin\ponyc.exe+0x1ba9a38)
2026-03-06T00:42:33.6510095Z #9 0x00007ff67068ae56 pony_asio_event_set_writeable (C:\ponyc\bin\ponyc.exe+0xd3ae56)
2026-03-06T00:42:33.6510871Z #10 0x00007ff6714fab25 pony_asio_event_set_writeable (C:\ponyc\bin\ponyc.exe+0x1baab25)
2026-03-06T00:42:33.6511656Z #11 0x00007ff670202162 pony_asio_event_set_writeable (C:\ponyc\bin\ponyc.exe+0x8b2162)
2026-03-06T00:42:33.6512421Z #12 0x00007ff66fb80682 pony_asio_event_set_writeable (C:\ponyc\bin\ponyc.exe+0x230682)
2026-03-06T00:42:33.6513552Z #13 0x00007ff670e3ccd0 pony_asio_event_set_writeable (C:\ponyc\bin\ponyc.exe+0x14eccd0)
2026-03-06T00:42:33.6514345Z #14 0x00007ff67066ba62 pony_asio_event_set_writeable (C:\ponyc\bin\ponyc.exe+0xd1ba62)
2026-03-06T00:42:33.6515100Z #15 0x00007ff66fb80682 pony_asio_event_set_writeable (C:\ponyc\bin\ponyc.exe+0x230682)
2026-03-06T00:42:33.6515819Z #16 0x00007ff66fa9cfce pony_actor_stats (C:\ponyc\bin\ponyc.exe+0x14cfce)
2026-03-06T00:42:33.6516491Z #17 0x00007ff66fa9ed36 pony_actor_stats (C:\ponyc\bin\ponyc.exe+0x14ed36)
2026-03-06T00:42:33.6517060Z #18 0x00007ff66fa8d143 (C:\ponyc\bin\ponyc.exe+0x13d143)
2026-03-06T00:42:33.6517528Z #19 0x00007ff66fa4a155 (C:\ponyc\bin\ponyc.exe+0xfa155)
2026-03-06T00:42:33.6517976Z #20 0x00007ff66f9f251f (C:\ponyc\bin\ponyc.exe+0xa251f)
2026-03-06T00:42:33.6518585Z #21 0x00007ff671911960 pony_asio_event_set_writeable (C:\ponyc\bin\ponyc.exe+0x1fc1960)
2026-03-06T00:42:33.6519272Z #22 0x00007ffc3451e8d7 (C:\Windows\System32\KERNEL32.DLL+0x2e8d7)
2026-03-06T00:42:33.6519839Z #23 0x00007ffc353cc53c (C:\Windows\SYSTEM32\ntdll.dll+0x8c53c)
2026-03-06T00:42:34.3247902Z �[31;1mmake.ps1: �[0mD:\a_temp\b0361f08-5c21-44f9-964f-1348582c1bf1.ps1:5�[0m
2026-03-06T00:42:34.3248795Z �[31;1m�[0m�[36;1mLine |�[0m
2026-03-06T00:42:34.3249786Z �[31;1m�[0m�[36;1m�[36;1m 5 | �[0m �[36;1m.\make.ps1 -Command unit-tests 2>&1�[0m
2026-03-06T00:42:34.3250620Z �[31;1m�[0m�[36;1m�[36;1m�[0m�[36;1m�[0m�[36;1m | �[31;1m ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~�[0m
2026-03-06T00:42:34.3251482Z �[31;1m�[0m�[36;1m�[36;1m�[0m�[36;1m�[0m�[36;1m�[31;1m�[31;1m�[36;1m | �[31;1mThe term 'D:\a\corral\corral\build\release\test.exe' is not recognized as a name of a cmdlet, function, script�[0m
2026-03-06T00:42:34.3252706Z �[31;1m�[0m�[36;1m�[36;1m�[0m�[36;1m�[0m�[36;1m�[31;1m�[31;1m�[36;1m�[31;1m�[36;1m | �[31;1mfile, or executable program. Check the spelling of the name, or if a path was included, verify that the path is�[0m
2026-03-06T00:42:34.3253647Z �[31;1m�[0m�[36;1m�[36;1m�[0m�[36;1m�[0m�[36;1m�[31;1m�[31;1m�[36;1m�[31;1m�[36;1m�[31;1m�[36;1m | �[31;1mcorrect and try again.�[0m
2026-03-06T00:42:34.3701197Z ##[error]Process completed with exit code 1.
2026-03-06T00:42:34.3954450Z ##[group]Run zulip/github-actions-zulip@e4c8f27
2026-03-06T00:42:34.3954960Z with:
2026-03-06T00:42:34.3955376Z api-key: ***
2026-03-06T00:42:34.3955643Z email: ***
2026-03-06T00:42:34.3955887Z organization-url: https://ponylang.zulipchat.com/
2026-03-06T00:42:34.3956183Z to: notifications
2026-03-06T00:42:34.3956339Z type: stream
2026-03-06T00:42:34.3956524Z topic: ponylang/corral scheduled job failure
2026-03-06T00:42:34.3956903Z content: https://github.com/ponylang/corral/actions/runs/22743479385 failed.
2026-03-06T00:42:34.3957772Z ##[endgroup]
2026-03-06T00:42:34.8404050Z Message successfully sent with id: 577625363
2026-03-06T00:42:34.8760130Z Post job cleanup.
2026-03-06T00:42:35.0834271Z [command]"C:\Program Files\Git\bin\git.exe" version
2026-03-06T00:42:35.1217517Z git version 2.53.0.windows.1
2026-03-06T00:42:35.1310035Z Temporarily overriding HOME='D:\a_temp\9bb5d74c-a0f9-4f3e-b5aa-f585380d8c73' before making global git config changes
2026-03-06T00:42:35.1311270Z Adding repository directory to the temporary git global config as a safe directory
2026-03-06T00:42:35.1318747Z [command]"C:\Program Files\Git\bin\git.exe" config --global --add safe.directory D:\a\corral\corral
2026-03-06T00:42:35.1667193Z [command]"C:\Program Files\Git\bin\git.exe" config --local --name-only --get-regexp core.sshCommand
2026-03-06T00:42:35.2033638Z [command]"C:\Program Files\Git\bin\git.exe" submodule foreach --recursive "sh -c "git config --local --name-only --get-regexp 'core.sshCommand' && git config --local --unset-all 'core.sshCommand' || :""
2026-03-06T00:42:35.7516819Z [command]"C:\Program Files\Git\bin\git.exe" config --local --name-only --get-regexp http.https://github.com/.extraheader
2026-03-06T00:42:35.7776396Z http.https://github.com/.extraheader
2026-03-06T00:42:35.7823296Z [command]"C:\Program Files\Git\bin\git.exe" config --local --unset-all http.https://github.com/.extraheader
2026-03-06T00:42:35.8126044Z [command]"C:\Program Files\Git\bin\git.exe" submodule foreach --recursive "sh -c "git config --local --name-only --get-regexp 'http.https://github.com/.extraheader' && git config --local --unset-all 'http.https://github.com/.extraheader' || :""
2026-03-06T00:42:36.3979742Z Cleaning up orphan processes
2026-03-06T00:42:36.4299566Z Terminate orphan process: pid (5316) (vctip)

[SeanTAllen]

I sent Claude off to do research on our previous HeapToStack issues, similar problems other projects have hit when calling InlineFunction from custom passes, and an analysis of LLVM 19/20/21 API changes that could cause us problems in HeapToStack. Here's what it found.

Our HeapToStack History

We've fixed HeapToStack bugs after LLVM upgrades before:

• Fix bug in HeapToStack optimization pass #4341 (LLVM 15 era): HeapToStack left tail annotations on calls that accessed alloca memory. Later passes would remove initialization code. Fix: mark all calls as not tail when converting any allocation to stack.
• Compiler crash in HeapToStack optimization #4059 (LLVM ~14 era): Call graph code cribbed from the D-Lang compiler during LLVM 4 support was used incorrectly. Innocuous for years until an LLVM change made it crash. Fix: remove the call graph code entirely.
• Use heap-to-stack workaround for Windows #3025 (LLVM 7): HeapToStack needed a Windows-specific workaround that wasn't previously necessary. Windows has consistently been the platform where HeapToStack edge cases surface first.

The Core Problem: InlineFunction from a Function Pass

The HeapToStack pass calls InlineFunction at line 199 of genopt.cc to force-inline constructors after converting heap allocations to stack. This has three independent correctness problems. Any one of them could be the crash.

1. CGSCC Contract Violation

HeapToStack is registered as a function pass via registerPeepholeEPCallback. It runs inside the CGSCC pipeline:

cgscc(devirt<4>(...,function<eager-inv;no-rerun>(...,HeapToStack,...),...)

Function passes are prohibited from introducing new call graph edges. When InlineFunction inlines a constructor, it copies all of the constructor's call instructions into the caller, creating new edges. LLVM enforces this with assertions in updateCGAndAnalysisManagerForFunctionPass:

assert((E || !FunctionPass) &&
       "No function transformations should introduce *new* "
       "call edges! Any new calls should be modeled as "
       "promoted existing ref edges!");

These assertions only fire in debug LLVM builds. In the release build we ship, the call graph becomes silently inconsistent.

LLVM's own CoroAnnotationElidePass hit the exact same crash (llvm/llvm-project#114487) when it was converted from a CGSCC pass to a function pass while still calling InlineFunction. The fix was to convert it back to a CGSCC pass.

2. Iterator Invalidation / Use-After-Free

Typical Pony IR puts the constructor call right after pony_alloc:

%ptr = call @pony_alloc(%ctx, 32)        ; ← inst, iter already advanced past
%obj = call @MyClass_create(%ptr, %arg)   ; ← iter now points HERE

The outer loop uses early increment (iter++ on line 101) to survive erasure of inst. But InlineFunction on the constructor call splits the basic block at the constructor call, clones the callee body, and erases the constructor call via CB.eraseFromParent().

LLVM's ilist_base::removeImpl explicitly nulls out the removed node's prev/next pointers:

// Not strictly necessary, but helps catch a class of bugs.
N.setPrev(nullptr);
N.setNext(nullptr);

If iter was pointing to the constructor call (because the early increment advanced it there), it's now a dangling iterator with null pointers. The next loop iteration dereferences null. Access violation.

3. Stale DominatorTree

The DominatorTree& dt is obtained once at line 91 and used for the entire function scan. After InlineFunction modifies the function, the DominatorTree is completely stale. If a second pony_alloc is found in the same function, canStackAlloc calls dt.dominates() with stale data.

Why Windows, Why Now

Windows is more aggressive about invalidating freed memory. On Linux, the erased instruction's memory might still contain valid-looking prev/next pointers by accident, so the dangling iterator "works." On Windows, the access violation fires immediately.

Three major LLVM versions of optimizer changes alter IR instruction ordering. Different ordering can put the constructor call right after pony_alloc in the same block (the dangerous pattern), where previously there may have been intervening instructions.

Secondary Issues (LLVM 19-21 API changes)

These don't directly cause this crash but are bugs waiting to happen:

• Deprecated Instruction* insertion points (LLVM 19+ RemoveDIs migration): Lines 173 and 185 unwrap iterators to Instruction*, losing the debug-info bit. Should pass iterators directly.
• moveBefore vs moveBeforePreserving in MergeMessageSend: moveBefore doesn't transfer attached debug records.
• Dangling pointers in new_calls vector: If there are multiple constructor calls, the first InlineFunction can invalidate pointers to later constructor calls.

Recommended Fix

Remove the InlineFunction call from HeapToStack (lines 191-201). HeapToStack runs inside devirt<4>(...), which re-runs the function simplification pipeline up to 4 times when call graph changes are detected. LLVM's own InlinerPass runs in the same CGSCC pipeline and will inline these constructors in a subsequent iteration. After inlining, HeapToStack runs again and can stack-allocate any field allocations exposed by the inlining. This eliminates all three correctness problems at once.

The tradeoff is that the optimization becomes iterative (across pipeline runs) rather than immediate (within a single HeapToStack invocation). The devirt<4> wrapper provides exactly this iteration mechanism.

Risk: Optimization Regression

The force-inlining was added deliberately (commit bbff5b5, "Force constructor inlining when stack-allocating objects"). LLVM's normal inliner might not inline Pony constructors on its own if they don't meet LLVM's cost threshold. If the inliner skips them, HeapToStack never sees the field allocations inside constructors, and we lose nested stack promotion. We'd want to measure this with --print-stats before and after, comparing heap_alloc vs stack_alloc counts.

Alternatives If Regression Is Real

1. Mark Pony constructors with alwaysinline during codegen. This would make LLVM's inliner do the work without us having to call InlineFunction ourselves. HeapToStack stays a function pass, the inliner handles the inlining in its own CGSCC pass, and HeapToStack picks up the exposed field allocations on the next pipeline iteration.

2. Convert HeapToStack to a CGSCC pass so it can properly call InlineFunction and update the call graph via updateCGAndAnalysisManagerForCGSCCPass. This is the approach LLVM took with CoroAnnotationElidePass. It's a bigger change but preserves the current optimization behavior exactly.

[SeanTAllen]

I tested the latest nightly against the corral tests and it didn't crash. So this is non-deterministic, which tracks with the analysis above.

If the root cause is iterator invalidation / use-after-free, the crash depends on memory layout — whether the freed instruction's memory gets reused or zeroed before the dangling iterator is dereferenced. Non-deterministic by nature.

The CGSCC contract violation side of it should be deterministic in a debug LLVM build though. Building ponyc against a debug LLVM would fire the assertion every time. That's a heavy lift just for confirmation, but it's there if we want a definitive answer.

[SeanTAllen]

For 1. we want to refactor to registering as registerCGSCCOptimizerLateEPCallback.

[SeanTAllen]

2: we are thinking:

but not insane.

      for(auto iter = block->begin(), end = block->end(); iter != end;)
      {
        Instruction* inst = &(*(iter));

        if (iter == block->begin())
        {
          if(runOnInstruction(builder, inst, dt, f))
          {
            changed = true;
            iter = block->begin();
          }
          else
          {
            iter++;
          }
        }
        else
        {
          // One step back
          --iter;
          if(runOnInstruction(builder, inst, dt, f))
            changed = true;
          // two steps forwards
          iter += 2;
        }
      }

[SeanTAllen]

3. get new dominator.