BashScriptsTests seems to be broken on macOS

[bishabosha]

I can't run dotty.tools.scripting.BashScriptsTests on macOS without consistently failing verifyScriptPathProperty, (and sqlDateTest) it appears no output is captured from invoked scripts in ScriptTestEnv.bashCommand, leading to assertion failures. However in the CI, it is fine

[griggt]

Just curious, did you first run dist/pack? I believe that is a precondition for this test and some other tests in dotty.tools.scripting (which is not obvious, and inconsistent with the rest of the compiler test suite)

[bishabosha]

I had a look at the GitHub action cli so I did run that before, but I'm not sure what else is happening

[bishabosha]

@philwalk the output can be seen here https://gist.github.com/bishabosha/5157676e96e01a79e6e59c8418114fdb,

from what I see, it looks like compiler/test-resources/scripting/scriptPath.sc is being interpreted as a bash file, and the shebang is not being activated.

so on macOS I can replace the shebang with #!/usr/bin/env dist/target/pack/bin/scala and now it works for me, (Edit, but not the CI)

[bishabosha]

I've included a fix in #15212

Edit: I removed it

[bishabosha]

@philwalk I tried to push a change to prepend /usr/bin/env to the shebangs of the problematic files in the gist. However the CI did not like it unless I also add the -S flag, which I think could be problematic when you are specifically testing the preprocessing of arguments, or is this safe to do?

So perhaps there is a way to set up the environment in the subprocess so that the scala script is available in the path when I run the test?

[bishabosha]

reopening due to revert of fix in #15259