boulder: Add build level lockfile functionality to avoid builds of the same recipe clobbering each other

[ermo]

tarkah
wen .. | xargs -n 1 -P 2 boulder .. lol
ermo
I've tried it. It doesn't work. boulders clobber each other's files.
it results in crashes
(unless they each run in their own container I suppose)
tarkah
Have you tried it since we implemented moss lockfile?
Shouldn't clobber anything now I don't think
ermo
yes, that's where I tried. Though the case may be that what I did wrong was to try it with the same recipe.
but in principle, should that really matter?
tarkah
Oh yeah lol
Same recipe == disaster
Since they share host binds to same folders

ermo
but in principle, should that really matter?

Yes
As in, it should succeed if different recipes because no folders overlap other than moss stuff
And moss stuff is lockfiled now
ermo
so that is effectively an (important!) implementation detail to be aware of?
meaning that boulder should actively check if the same recipe is already building?
and abort if it is?
tarkah
Oh yeah, we should have build level lockfiles maybe
Yeah
ermo
want me to capture an issue for it?
tarkah
Sure