gasnet-2020.3.0-2.fc33 fails to build in Fedora 33:

+ ../configure --build=x86_64-redhat-linux-gnu --host=x86_64-redhat-linux-gnu --program-prefix= --disable-dependency-tracking --prefix=/usr --exec-prefix=/usr --bindir=/usr/bin --sbindir=/usr/sbin --sysconfdir=/etc --datadir=/usr/share --includedir=/usr/include --libdir=/usr/lib64 --libexecdir=/usr/libexec --localstatedir=/var --sharedstatedir=/var/lib --mandir=/usr/share/man --infodir=/usr/share/info --enable-udp --disable-mpi --enable-par --disable-aligned-segments --disable-ibv --enable-segment-fast --with-segment-mmap-max=4GB 'CC=gcc -fPIC' 'CXX=g++ -fPIC'
[...]
checking atomic implementation family (binary probe)... 14294967297
configure error: Invalid GASNETI_ATOMIC_IMPL detected
configure: error: See /builddir/build/BUILD/GASNet-2020.3.0/serial/config.log for details.

A difference between passing and failing build root is at <https://koschei.fedoraproject.org/build/8625119>.