https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85526
--- Comment #4 from Pietro Delugas <mail at pietrodelugas dot it> --- a quick and dirty workaround is to move all the routines in the "leng" interface at the bottom of the file. But some compilers do not accept this code as valid. A better solution is to move the leng subroutines in a module by their own and import the interface.