[bug-diffutils] bug#24330: mingw64: diff complains about the argument '-' (stdin), not able to run testsuites generated by automake [side issue: not able to compile diffutils-3.5]

[Simon Sobisch]

I'd rather like to see MinGW builds for the upcoming GnuCOBOL 2.0
release than a VisualStudio build just "because it compiles directly and
the MinGW build does not".

Concerning diff this is "only" a testsuite issue but I can hope you can
help me clearing things up.

It all started with running the testsuite and mostly getting failures.

After some investigations (and fixing a borked -R linker parameter) we
found that nearly everything works - but the testsuite still fails with
the output:

        C:\msys64\mingw64\bin\diff.exe: -: Invalid argument

The user tried hard in the hope that rebuilding diffutils would help -
he got into the known issue "bug#24304".

Side note: I've seen
http://lists.gnu.org/archive/html/bug-diffutils/2016-08/msg00052.html
and wonder where exactly this bug/wish-list item is tracked (I did not
seen any trackers at savannah).

I highly suggest to at least add an error during ./configure about the
not working environment (maybe adding the link to the bug report)
instead of leaving the user with a broken compilation.


Back to the main question of this post:
Do you have any idea how to fix "-: Invalid argument"? Where should we
look at (the user compiled diffutils 3.3 with some unoffical patches but
the problem persists).

Thank you,
Simon