It seems the tests are failing because the tests directory in the crate does not contain all the subdirectory like in the repo:
$ ll tests/
drwxr-xr-x@ - bob 12 Jul 20:09 toml-missing-file
.rw-r--r--@ 468 bob 1 Jan 1970 testanotherlib.pc
.rw-r--r--@ 176 bob 1 Jan 1970 testdata.pc
.rw-r--r--@ 229 bob 1 Jan 1970 testlib-2.0.pc
.rw-r--r--@ 229 bob 1 Jan 1970 testlib-3.0.pc
.rw-r--r--@ 290 bob 1 Jan 1970 testlib.pc
Shouldn't all the tests subdirectories be included in the crate?