Re: [Mingw-users] How to set gfortran to process the include files in C/C++ format

[George K. <xke...@ne...>]

Your errors are in libslepc.a and libpetsc.a, so your problem is with 
those libraries. I am guessing that someone compiled libslepc.a and 
libpetsc.a to use Cygwin.

Your undefined references were
libslepc.a => srand48
libpetsc.a => __getreent, memalign, gethostbyname, htons, socket, 
connect, __errno, sleep

I see functions from Unix (srand48, memalign, sleep) and from BSD 
sockets (gethostbyname, htons, socket, connect), but __getreent and 
__errno seem weird. I ducked for "__getreent" and got references to 
Cygwin. I guess that __errno also comes from Cygwin, because MinGW has 
_errno with one underscore, not __errno with two underscores.

In MinGW, <errno.h> defines errno as

_CRTIMP int* __cdecl __MINGW_NOTHROW _errno(void);
#define    errno        (*_errno())

If you have a Cygwin version of libslepc.a and libpetsc.a, you can't use 
them with MinGW. You might want the Cygwin version of gfortran. I don't 
use Cygwin, but I remember that Cygwin has its own gcc.
--George Koehler