Use the same temp personal module path when env 'HOME' not defined

[daxian-dbw]

PR Summary

Fix #13189

When the env variable HOME is not defined, every Runspace startup on Unix platforms will try creating a folder in the form of /tmp/<new-guid>/.local/share/powershell/Modules as the personal user module path. That means LOTs of such folders get created when Foreach-Object -Parallel is dealing with a lot of inputs. In that situation, it may not be surprising to see strange failures like the DirectoryNotFoundException reported in the issue.

This PR adds a static field to cache the temporary personal user module path, so all Runspace's will use the same temp directory path in case HOME env variable is not defined.

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[rjmholt]

N/A or can only be tested interactively

I wonder if it's possible to test this by unsetting $env:HOME

[PaulHigin]

Thanks for fixing this! I don't think we need tests for this change, and as long as current tests pass I feel we are good.

[rjmholt]

@PoshChan please remind me in 23 hours

[iSazonov]

You assume that HOME could be defined on the fly (and preserve current behavior) but we could already put some files in previous folder :-(

[daxian-dbw]

Sorry that I missed this comment. I think it would be very unlikely that the HOME env var changes it value after it's declared, so I'm not too worry about this.

[PoshChan]

@rjmholt, this is the reminder you requested 23 hours ago

[iSazonov]

Will be this backported to 7.0?

[rjmholt]

Will be this backported to 7.0?

@PaulHigin @daxian-dbw

[daxian-dbw]

Good question. Maybe it's worth backporting, given the fix is so simple.
Marked this PR maintainer - review

[ghost]

🎉v7.1.0-preview.6 has been released which incorporates this pull request.:tada:

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[ghost]

🎉v7.0.4 has been released which incorporates this pull request.:tada:

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