This only happens with default CFLAGS (-g -O2). This example is using gcc 8.2 and mpich 3.2.1.

mpicc -DDARSHAN_CONFIG_H=\"darshan-runtime-config.h\" -I . -I.. -I../../ -g -O2  -D_LARGEFILE64_SOURCE -shared -fpic -DPIC -DDARSHAN_PRELOAD -c ../lib/darshan-stdio.c -o lib/darshan-stdio.po
In file included from /usr/include/stdio.h:873,
                 from ../lib/darshan-stdio.c:65:
../lib/darshan-stdio.c: In function ‘fprintf’:
/usr/include/x86_64-linux-gnu/bits/stdio2.h:98:1: error: inlining failed in call to always_inline ‘fprintf.localalias.1’: redefined extern inline functions are not considered for inlining
 fprintf (FILE *__restrict __stream, const char *__restrict __fmt, ...)
 ^~~~~~~
In file included from ../darshan.h:17,
                 from ../lib/darshan-stdio.c:84:
../darshan-module-api.h:49:13: note: called from here
             fprintf(stderr, "Darshan failed to map symbol: %s\n", #__func); \
             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../lib/darshan-stdio.c:540:5: note: in expansion of macro ‘MAP_OR_FAIL’
     MAP_OR_FAIL(vfprintf);
     ^~~~~~~~~~~
make: *** [Makefile:143: lib/darshan-stdio.po] Error 1