I ran into something similar a while back and it turned out not to be the merge itself, but how the manuals are actually wired into the build system.
A couple of things worth checking:
1. --enable-manuals usually just enables the rules, but the toolchain for generating PDFs has to be present (dblatex, xsltproc, latex, etc., depending on how your project does it). If any of those are missing, make will happily say there’s nothing to do. 2. In some setups only HTML gets built by default; PDF targets are conditional. Try make clean and then make manuals or make doc-pdf if such a target exists. For example, check website: https://brainrot-clicker.io 3. Check whether the manuals are now in a subdirectory like doc/ or manual/ in each repo — they might be building to a different output path than before. 4. Finally, after the merge, verify that the Makefile.am / CMakeLists actually includes the manuals directory. Sometimes the repo move breaks relative paths, so the build system literally doesn’t “see” any sources to generate PDFs from.