Switch-Process (exec) fails to make the replacement process inherit the calling process' environment variables

[mklement0]

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Steps to reproduce

It is understood that the newly introduced, Unix-only Switch-Process cmdlet (alias exec) is not designed to have full feature parity with the exec built-in in POSIX-compatible shells, notably not with respect to supporting stream redirections.

However, making the replacement process inherit the caller's environment is an important part of exec functionality (and it is how it works in POSIX-compatible shells).

Related discussion predating Switch-Process:

• Use start-Process start any process with PID 1 as exec do in bash #12750

# Run on macOS or Linux.
# Note the use of `exec`; if you remove it, 'bar' prints as expected
pwsh -nop -c '$env:FOO=''bar''; exec /bin/sh -c ''echo $FOO'''

Expected behavior

bar

Actual behavior

(no output)

Error details

No response

Environment data

PowerShell Core 7.3.0-rc.1 on Unix-like platforms

Visuals

No response

[SteveL-MSFT]

Based on what I could find, execv() is supposed to automatically propagate the current env to the new process. However, may need to switch to execve() to copy the env.