[Bug libfortran/63471] [5.0 Regression] unix.c:1906:10: error: implicit declaration of function 'ttyname_r'

[jb at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63471

--- Comment #2 from Janne Blomqvist <jb at gcc dot gnu.org> ---
Hmm, maybe add something like

AC_CHECK_DECLS_ONCE([ttyname_r])

to configure.ac and then in unix.c(stream_ttyname) check with

#ifdef HAVE_TTYNAME_R && HAVE_DECL_TTYNAME_R