This program is not same to the Rust version. A more faithful version, assuming glibc, would look like this: #include <stdio.h> #include <stdlib.h>

This program is not same to the Rust version. A more faithful version, assuming glibc, would look like this: #include <stdio.h> #include <stdlib.h> #include <execinfo.h> #include <errno.h> void print_backtrace(void) { void *traces[50]; char **symbols; int num_traces, i; num_traces = backtrace(traces, sizeof(traces) / sizeof(*traces)); strings = backtrace_symbols(traces, num_traces); if (!strings) return; for (i = 0; i < num_traces; ++i) { fprintf("%d: %s\n", i + 1, strings[i]); } free(strings); } int main(void) { static const char FMT[] = "Hello, World!\n"; static int EXPECTED = (int) (sizeof(FMT) - 1); int ret = printf(FMT); if (ret < 0) { fprintf(stderr, "printf failed: %s\n", strerror(errno)); print_backtrace(); return 1; } if (ret != EXPECTED) { fprintf(stderr, "printf failed: only %d characters were written\n", ret); print_backtrace(); return 1; } return 0; } While this is still substantially different (for example, Rust's I/O buffering is different from C), this should be enough to demonstrate that this comparison is very unfair.