$> spack install darshan-runtime
...
==> Error: Failed to install darshan-runtime due to ChildError: ProcessError: Command exited with status 2:
    'make' '-j16'
1 error found in build log:
     99     ar rcs lib/libdarshan-stubs.a lib/darshan-pnetcdf-stubs.o
     100    ../darshan-runtime/lib/darshan-core.c: In function 'darshan_get_exe_and_mounts':
     101    ../darshan-runtime/lib/darshan-core.c:1150:13: warning: ignoring return value of 'fgets', declared with attribute warn_unused_result [-Wunused-re
            sult]
     102     1150 |             fgets(cmdl,DARSHAN_EXE_LEN,fh);
     103          |             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     104    /tmp/ccpXnisF.s: Assembler messages:
  >> 105    /tmp/ccpXnisF.s:8281: Error: symbol `__isoc99_fscanf' is already defined
     106    make: *** [Makefile:143: lib/darshan-stdio.po] Error 1
     107    make: *** Waiting for unfinished jobs....

See build log for details:
  /tmp/root/spack-stage/spack-stage-darshan-runtime-3.1.8-75i6acapt7rptrmgkibmuizjlciagw4a/spack-build-out.txt