[julia] Install the CompilerExplorer.jl after installing the compiler

[giordano]

This is my initial attempt to address #1259, but there are still things I don't understand, so opening as draft.

CC: @vchuravy.

[giordano]

Can I define custom fields in this yaml file? I did it for convenience, to avoid repeating some things, but if it doesn't work I'll change this;

[mattgodbolt]

you can; and that's the intention to let you cascading-ly refer to things later on as you do.

[giordano]

I have no clue what path destination is, I saw it in

infra/bin/yaml/haskell.yaml

Line 14 in f7d9fb5

- ./configure --prefix={destination}/{dir}

but I don't know if {destination}/depot is something like /opt/compiler-explorer/julia-{name} or what.

[mattgodbolt]

You may need to quote some of these things to make them valid yaml

[giordano]

Is bin/julia (== {julia_exe}) a sensible way to call the julia executable after it has been installed? I followed the check_exe example.

[vchuravy]

Suggested change

	- JULIA_DEPOT_PATH={depot} {julia_exe} -e 'using Pkg; Pkg.add(; url="https://github.com/giordano/CompilerExplorer.jl", rev="{ce_revision}"); Pkg.precompile()'
	- JULIA_DEPOT_PATH={depot}: {julia_exe} -e 'using Pkg; Pkg.add(; url="https://github.com/giordano/CompilerExplorer.jl", rev="{ce_revision}"); Pkg.precompile()'

Any reason for using {depot} instead of {destination}/local/share/julia?

We likely also need a project + manifest in the LOAD_PATH

[giordano]

I was planning adding the package to the global environment, so that we don't have to deal with adding a Project.toml/Manifest.toml here (the latter file being problematic, since it's different for each julia version). But I'm open to better solutions.

[vchuravy]

So if you use the local depot https://docs.julialang.org/en/v1/base/constants/#Base.DEPOT_PATH

Then we don't need to modify the depot path later one.

I don't think we want to use the default project since the user might try to modify it and this is read-only (might also be fine).

You need : after the path so that we still have the system depot available for the stdlib

[giordano]

In order to set JULIA_DEPOT_PATH=/path/to/depot, in https://github.com/compiler-explorer/compiler-explorer/blob/042e2b1c02416ac7039d050bbccba726e1e7ddaf/lib/compilers/julia.ts we need to override getDefaultExecOptions to add JULIA_DEPOT_PATH=... to the environment, right?

[partouf]

In order to set JULIA_DEPOT_PATH=/path/to/depot, in https://github.com/compiler-explorer/compiler-explorer/blob/042e2b1c02416ac7039d050bbccba726e1e7ddaf/lib/compilers/julia.ts we need to override getDefaultExecOptions to add JULIA_DEPOT_PATH=... to the environment, right?

correct