Hi Kevin,
see here for some known to fail testcases: https://downloads.uclibc-ng.org/reports/1.0.46/REPORT.riscv64.libc.uClibc-ng...
22 test failures. And that is without locale.
The riscv64 port is not perfect, yet. It is only tested with rv64imac. Init from busybox segfaults with rv64imadc.
I can reproduce your problems with gcc and git inside Qemu. Need to dig deeper.
best regards Waldemar