All of this is false, including the last statement. Proof by existence: Solaris/Illumos has a thread-safe (leaking, though the leaks are hidden from memory deb

All of this is false, including the last statement. Proof by existence: Solaris/Illumos has a thread-safe (leaking, though the leaks are hidden from memory debuggers), lock-less (whenever you don't write to `environ`) `getenv()`, and thread-safe, locking `setenv()`/`putenv()`/`unsetenv()`: https://src.illumos.org/source/xref/illumos-gate/usr/src/lib/libc/port/gen/getenv.c?r=60b81b86#48 https://src.illumos.org/source/xref/illumos-gate/usr/src/lib... Yes, it can be done and has been done. glibc has no excuse.