Oops, I forgot I fixed this in git after tagging v232 (commit 8024fc6171). I now added -Werror=implicit-function-declaration to compile flags so the compilation should actually fail instead of just emitted a warning if the same problem occurs hain.
You probably want to pull in most of those: * 84fcfc05e5 setup.py: make build fail if undeclared symbols are used * 911591a118 build-sys: import "pytest" instead of "py.test" * 8024fc6171 _reader: use proper ifdef guard for sd_j_open_files_fd * 35a5b281ad tests: add workaround for pre-232 system returning EINVAL on some flags * b9767792b9 docs: fix sphinx format warning * 177ac6d894 tests: skip fdstore tests if not implemented Zbyszek