The build log:
** Unknown command `@code' (left as is) (in src/doc/muxers.texi l. 2020)
*** '{' without macro. Before: -map} option with the ffmpeg CLI tool. (in src/doc/muxers.texi l. 2020)
*** '}' without opening '{' before: option with the ffmpeg CLI tool. (in src/doc/muxers.texi l. 2020)