Cannot make from source or opam

[mjm2000]

when running make after cloning the repo, I get

make: mkdir: Permission denied
make: *** [Makefile:155: src/ocamlbuild_pack.cmo] Error 127 

When I run "opam install ocamlbuild" I get the same. I'm on Manjaro Linux Kernal 5.4

[gasche]

This is fairly strange. The command that appears to be failing is mkdir -p tmp (creating a tmp repository in the current directory, if it does not already exist). I don't see how that would fail with "permission denied". Do you indeed have the rights on the directory of the clone ? (I assume so.) Maybe add a pwd at the beginning of the src/ocamlbuild_pack.cmo rule to check that you are indeed in the expected (current) directory at the time this command is launched.