With large projects and long paths, the call to ByteCodeLinker.exe (which needs all .bc files) could become too large for the Windows command line limits (32768 chars). In https://gitlab.science.ru.nl/clean-and-itasks/abc-interpreter/merge_requests/116 I added a -f option to the linker to be able to read input files from a separate file; this patch uses that in cpm/the IDE.
!22 (merged) is still useful to give meaningful error messages should the same problem occur elsewhere in the future.