It was for me totally impossible without further directions from someone who is responsible for the perl modules on LEDE to set up any environment to build them correctly.
You have problems with:
-
musl: means you can not use binary modules from other linux distros which don't use musl and i found none except LEDE that uses musl.
-
incomplete perlbase-devel: means you can not compile perl modules on the machine itself; providing these from a new compiled perl source is also impossible; see next point.
-
GCC vs CCACHE; for perl on LEDE ccache was used as C-compiler. Modules need the exact same compiler environment as was used to compile perl itself. So it is impossible to add gcc compiled modules and gcc is the only compiler provided by LEDE.
-
Cross-Compiling: not sure how that would work, since missing modules are built on the running system through CPAN which would mean setting up a cross compile build environment for LEDE and for CPAN. Not sure if this is even possible with CPAN since it does a lot of tests with a built component within the running perl environment.
So i went another route.
I created what is called "DebianWRT" on the web:
-
install LEDE and use it as a base system with all needed kernel modules and software to access hardware and do the routing part
-
use debootstrap to install a debian-system in a fresh directory and chroot to it. Install PERL and FHEM to the chroot environment. Debian PERL provides all missing PERL modules.