FWIW, this sounds like a slightly different problem than the OP. An unintuitive property of static libraries is that if you are producing a static archive that contains Swift code, the build system does not keep track of the associated .swiftmodule files, because they are separate artifacts from the .a archive. In this case you need to manually add -add_ast_path /path/to/mystaticarchive.swiftmodule to the linker flags of every binary or dylib that links against the static archive.

An unintuitive property of static libraries is that if you are producing a static archive that contains Swift code, the build system does not keep track of the associated .swiftmodule files, because they are separate artifacts from the .a archive. In this case you need to manually add -add_ast_path /path/to/mystaticarchive.swiftmodule to the linker flags of every binary or dylib that links against the static archive.

An unintuitive property of static libraries is that if you are producing a static archive that contains Swift code, the build system does not keep track of the associated .swiftmodule files, because they are separate artifacts from the .a archive. In this case you need to manually add -add_ast_path /path/to/mystaticarchive.swiftmodule to the linker flags of every binary or dylib that links against the static archive.