This seems to be a Heisenbug. I cannot reproduce it every time, though it certainly happens[1].
I am not sure I have seen this on a build running through from start to finish. So this _might_ be something that only happens when restarting a partial build. (Which is not that uncommon for LibreOffice and because of its size one is less likely to throw away and start again for this hours long builds).
This seems to be a Heisenbug. I cannot reproduce it every time, though it certainly happens[1].
I am not sure I have seen this on a build running through from start to finish. So this _might_ be something that only happens when restarting a partial build. (Which is not that uncommon for LibreOffice and because of its size one is less likely to throw away and start again for this hours long builds).
[1] see https:/ /www.reddit. com/r/linux/ comments/ 4ocwft/ a_third_ of_a_libreoffic e_snap_ lo_snap_ size/d4bm2mw for a particulary embarrassing instance.