I have a question about do_tzset() function implementation (musl v1.1.5). The function has the following conditions to prevent timezone file remapping

if (old_tz && !strcmp(s, old_tz)) return;

which do not allow to use "TZ" environment variable pointing to the same file (e.g. /etc/localtime). But some distros replace this file directly or use it as a symlink.