Building LLVM on CI seems broken after Deps: after configuring CMake project, use cmake --build, not make ( #54538)

[Zentrik]

After 8fd5aeb, building LLVM on CI as part of JuliaCI/julia-buildkite#345 just seems to hang until a cancellation signal at which points it starts building again. See https://buildkite.com/julialang/julia-buildkite/builds/1608#0190f950-0eb6-4fe3-938b-af69d186c40a for an example log with -d passed to make.

I'm not sure why this is happening, but given 8fd5aeb seemed to have some other issues (see #55091) I'm inclined to just revert it.

[vtjnash]

Maybe it just needs to be prefixed with + to make the jobserver work correctly? Or make sure we aren't running one of the broken kernels from circa 2019-2021?

[Zentrik]

I tried adding a + in JuliaCI/julia-buildkite@bee6422 (#345) but I probably misunderstood something as I just got the error .buildkite/utilities/build_julia.sh: line 55: +make: command not found.
I'm not sure what the broken kernels you're referring to are.

[vtjnash]

The linux kernel epoll syscall was broken for several versions. The + goes in the makefile, not the call to it

[giordano]

To elaborate, what Jameson was referring to was to add + at the beginning of the relevant line of a rule, to make it execute like make -n