[th/cli-fork-safety] avoid setenv() after fork
after fork (before exec) only functions from man signal-safety
can be used. Avoid using setenv()
to setup the pager.
setenv()
actually cannot be used safely anywhere, because glib applications are frequently multithreaded (e.g. if they use GDBus, which can happen already before main()
starts). In any case, it's also unsafe after fork.