std.posix.errno fails when syscall fails and libc is linked

[ProkopRandacek]

Zig Version

0.13.0-dev.46+3648d7df1

Steps to Reproduce and Observed Behavior

The std.posix.errno function contains a check if libc is linked. if it is, then it assumes that a syscall will return -1 on failure and set the C's errno value. It seems like it assumes when libc is linked then all syscalls are made using the libc. The problem is that some syscalls dont have a libc wrap (such as perf_event_open) so it still calls the raw syscall

When the syscalls fails the errno wrongly returns SUCCESS and then the perf_event_open .SUCCESS intCast crashes.

I guess better solution could be two separate errno functions, one for syscalls and one for libc functions?

Expected Behavior

No crash, corrent error returned.