Misleading error message for missing path-based dependency used as build helper

[ianprime0509]

Zig Version

0.14.0-dev.2546+0ff0bdb4a

Steps to Reproduce and Observed Output

Check out the build-dependency-path branch of https://github.com/ianprime0509/pathological-packages (commit 6be4a689b948bf5032156f488ae2d7cabf131fc9). This is a simple example of a project with a dependency specified using path in build.zig.zon which imports that dependency in build.zig as a build helper. Running zig build --help on the project as-is shows that a do-something step has been added to the build.

Now, change the path of the helper dependency in the root build.zig.zon to an incorrect path, such as ./invalid/helper. Run zig build --help again, and now the output is as follows:

/var/home/ian/src/pathological-packages/build.zig:2:24: error: no module named 'helper' available within module root.@build
const helper = @import("helper");
                       ^~~~~~~~
referenced by:
    build: /var/home/ian/src/pathological-packages/build.zig:5:5
    runBuild__anon_4419: /var/home/ian/src/zig/lib/std/Build.zig:2388:33
    6 reference(s) hidden; use '-freference-trace=8' to see all references

Expected Output

The error message should mention that the incorrect path in build.zig.zon does not exist or does not refer to a package which can be imported as a build helper (e.g. if the path exists but does not contain a build.zig).

For comparison, invoking b.dependency("helper", .{}) in the same project with the invalid path yields the following error, which does contain this context:

unable to open '/var/home/ian/src/pathological-packages/invalid/helper': FileNotFound
error: the following build command failed with exit code 1:
/var/home/ian/src/pathological-packages/.zig-cache/o/348eb32a6d21a299b246f2bdb33dbcb8/build /var/home/ian/src/zig/build/stage3/bin/zig /var/home/ian/src/zig/lib /var/home/ian/src/pathological-packages /var/home/ian/src/pathological-packages/.zig-cache /var/home/ian/.cache/zig --seed 0x5063ab2 -Z3a012f4b1ad78b7c --help