don't use realpath in Sys.which

[stevengj]

As discussed recently on discourse, some programs require a certain executable name to function correctly, and behave badly if you call realpath to expand symbolic links (potentially changing the program name).

#26559 by @staticfloat implemented Sys.which, but there doesn't seem to have been any discussion about whether realpath was a good idea.

[stevengj]

Actually, @vtjnash noted in #26559 (comment) that realpath would be "divergent from the which program, which does no normalization at all", so I'm not sure why we ended up using realpath.

[giordano]

Test failures look related (I think tests are specifically testing the use of realpath).

[stevengj]

Updated the tests to use abspath rather than realpath.

[stevengj]

Tests are green; should be good to merge.

[stevengj]

Or at least, the tests were green. Now I'm seeing an apparently unrelated error:

Error in testset cmdlineargs:
Error During Test at /Users/julia/buildbot/worker-tabularasa/tester_macos64/build/share/julia/test/testdefs.jl:21
  Got exception outside of a @test
  LoadError: could not load library "libjulia"

[vtjnash]

Looks like this is failing a spawn test on Win64?

[vtjnash]

That macOS failure is fixed on master

[stevengj]

Whoops, yes, now it is failing that test because of the .exe suffix.

Error in testset spawn:
Test Failed at C:\buildbot\worker-tabularasa\tester_win64\build\share\julia\test\spawn.jl:666
  Expression: p == joinpath(abspath("bin1"), "bar")
   Evaluated: "C:\\Windows\\TEMP\\jl_VxLh9u\\bin1\\bar.exe" == "C:\\Windows\\TEMP\\jl_VxLh9u\\bin1\\bar"

I just pushed a commit to fix that.