As of man-db-2.6.0.2, the command autoreconf -fi produces invalid configure:
autoreconf -fi
configure
./configure: line 37157: syntax error near unexpected token `libpipeline,' ./configure: line 37157: `PKG_CHECK_MODULES(libpipeline, libpipeline >= 1.1.0)'
Note that the build process does not involve any third-party patches.