mod/sub default targeting an hidden directory is not correctly resolved

[xdelaruelle]

With deep modules, when the default symbol for a sub-directory targets a directory whose name starts with a dot character (.), resolution of this default module fails:

$ cat mp/mod/
1.0        .modulerc  subdir/    
$ cat mp/mod/1.0 
#%Module
$ cat mp/mod/subdir/.subdir/2.0 
#%Module
$ cat mp/mod/.modulerc 
#%Module
module-version mod/subdir/.subdir default
$ module use mp
$ module load mod/subdir
ERROR: Unable to locate a modulefile for 'mod/subdir'