For versions 1.38 and later (else check the manual inside the older source):
For source extracted from a tar file:
cd recoll-xxxmeson setup[options]buildninja -C build
For a git clone, the procedure is almost the same, but the top of the source is the
src subdirectory. Showing an out of tree build (which you could of
course also use for the above tar extracion).
cd /some/where/meson setup[options]/path/to/recoll/src recollbuildninja -C recollbuild

