Include the current working dir in FileNotFoundError

Feature or enhancement

A FileNotFoundError exception should include the current working directory when referring to a relative path.

Pitch

The problem this solves is with relative paths. If you just get the error "foo/bar not found", it is not enough info to fully understand the problem, because whether this can be found depends on the working directory as well.

At the moment, I'm working with Bazel (a build system), which does its form of sandboxing by symlinking things into a separate directory and building there. This implies both creating files/symlinks and switching directories and a lot of that. When a file is not found, it can mean that either of the two operations were faulty, but with a relative path you absolutely need the working directory to say which is the case.

Note that there is another category of similar problems, where e.g. Popen() tries to locate an executable using the PATH environment variable. Here, the simple executable file name is not helpful without the directories that were searched.

Previous discussion

I have found #60389, which is also related to missing info in such an error. Apart from that, I haven't found any similar discussions.

Linked PRs

• gh-116071

Start by tracing where Python raises FileNotFoundError for relative paths and review the related Popen() behavior mentioned in the issue. The change is complete when a missing relative path reports the current working directory while preserving useful error behavior for paths resolved through PATH.