http://www.perlmonks.org?node_id=766751


in reply to Re^2: Error building Perl under cygwin
in thread Error building Perl under cygwin

It's hard to diagnose remotely why those tests failed...  As a start, you could try to run those failing tests manually, e.g.

$ PERL_CORE=1 ./perl ext/IPC/SysV/t/ipcsysv.t

(run this from the main build directory wherein the new perl has been created)

You should then see more output which might help figuring out what's wrong.  Also look at the respective .t sources to see what exactly those tests are testing...