fix(deps): improve error messages in dependency finding (#70)

- Convert version values to strings in error message formatting to handle non-string types
- Update CHANGELOG.md to document the improvement

Co-authored-by: Christopher Doris <github.com/cjdoris>

Author: cjdoris

CHANGELOG.md

@@ -1,5 +1,8 @@
 # Changelog
 
+## Unreleased
+* Improve some error messages.
+
 ## v0.1.18 (2025-09-01)
 * Support editable dependencies from setuptools (experimental).
 * Add `update()` function.

src/juliapkg/deps.py

@@ -373,7 +373,7 @@ def merge_compat(dep, kfvs, k):
                     "'{}' entries have empty intersection:\n{}".format(
                         k,
                         "\n".join(
-                            ["- {!r} at {}".format(v, f) for (f, v) in fvs.items()]
+                            ["- {!r} at {}".format(str(v), f) for (f, v) in fvs.items()]
                         ),
                     )
                 )
@@ -408,7 +408,9 @@ def merge_any(dep, kfvs, k):
     if compat is not None and not compat:
         raise Exception(
             "'julia' compat entries have empty intersection:\n{}".format(
-                "\n".join(["- {!r} at {}".format(v, f) for (f, v) in compats.items()])
+                "\n".join(
+                    ["- {!r} at {}".format(str(v), f) for (f, v) in compats.items()]
+                )
             )
         )
     return compat, deps