make check-fast fails at bootstrap-from-c-with-green on Windows

[retep998]

When running make check-fast on Windows using msys, all the tests pass up to this point where apparently gcc can no longer be found.

maketest: bootstrap-from-c-with-green
----- a:/Files/Coding/rust/src/test/run-make/bootstrap-from-c-with-green/ ------
--------------
------ stdout ---------------------------------------------
make[1]: Entering directory `/a/Files/Coding/rust/src/test/run-make/bootstrap-fr
om-c-with-green'
PATH="/a/Files/Coding/rust/i686-pc-mingw32/test/run-make/bootstrap-from-c-with-g
reen:a:/Files/Coding/rust/i686-pc-mingw32/stage2/bin:/a/mingw64/mingw32/opt/bin:
/a/mingw64/mingw32/bin/:/a/mingw64/mingw32/opt/bin/:/usr/bin/:/c/Program Files (
x86)/Git/bin/:/c/Windows/System32/" a:/Files/Coding/rust/i686-pc-mingw32/stage2/
bin/rustc.exe --out-dir /a/Files/Coding/rust/i686-pc-mingw32/test/run-make/boots
trap-from-c-with-green -L /a/Files/Coding/rust/i686-pc-mingw32/test/run-make/boo
tstrap-from-c-with-green lib.rs
make[1]: Leaving directory `/a/Files/Coding/rust/src/test/run-make/bootstrap-fro
m-c-with-green'

------ stderr ---------------------------------------------
error: could not exec the linker `gcc`: file not found (OS Error 2: The system c
annot find the file specified.
)
error: aborting due to previous error
make[1]: *** [all] Error 101

------        ---------------------------------------------

make: *** [i686-pc-mingw32/test/run-make/bootstrap-from-c-with-green-2-T-i686-pc
-mingw32-H-i686-pc-mingw32.ok] Error 2

I use this as my path:

PATH=/a/mingw64/mingw32/bin/:/a/mingw64/mingw32/opt/bin/:/a/mingw64/msys/1.0/bin/:/c/Program\ Files\ \(x86\)/Git/bin/:/c/Windows/System32/

Considering rust itself built fine and all the prior tests ran fine, I'm confused as to why gcc suddenly can no longer be found. And yes, I tried removing the Git portion to see if it was those spaces causing issues, and it still resulted in the same error.

[schmee]

I got something like this as well in #15250, probably related!

[retep998]

Oddly enough, running the tests from cmd with a windows style path with backslashes and semi-colons seems to work fine, although it frequently pops up dialogs complaining about missing dlls. I'm now rebuilding rust entirely from cmd to see how things work.

EDIT: A freshly rebuilt rust from cmd still has the same missing dll dialogs. I'm not exactly sure if thats bad or not since the tests continue on regardless and don't report any failures.