Package directories query

[StefanKarpinski]

@world-peace

• By a root project file, my understanding is this would be a Project.toml file in the root of the whole project directory. This is the same directory where each of the packages would live. So it looks like

my-project-root/
  Project.toml
  PackageA/
  PackageB/

Yes, that’s right. And it could be laid out like that. But one of the advantages of the dev approach is that it doesn’t matter where you put the dependencies—you can structure it however you want to as long as various path entries point to the correct locations.

dev all internal packages just means run julia --project=. in the my-project-root directory, enter the pkg REPL, and do dev ./PackageA, dev ./PackageB

Yes, but you can also activate the packages themselves and add dependencies between them in the same way. For example, if PackageB depends on PackageA then you would cd into PackageB, activate it and do pkg> dev ../PackageA in order to add a dependency on PackageA.

If you insist on using a package directory instead - this is where I get lost. What I have described above is a Package Directory, AFAIK ?

No, a “Package Directory” is a directory containing package that is put into the load path. In this approach you do not modify the load path.

no need to push all the dependency directories into the LOAD_PATH - again a bit lost here - are you essentially saying not to follow the suggestion from @g-gundam ?

You were talking about doing this:

push!(LOAD_PATH, "PackageA")
push!(LOAD_PATH, "PackageB")

and so on for each dependency. This will not work because it would cause code loading to look for packages inside of the PackageA and PackageB directories, which is not where you would find them. What you would do if you were using this approach is simply push!(LOAD_PATH, ".") because the top-level directory is the “Package Directory”, ie a directory that contains packages (which are directories, typically).

in fact, that won’t work—you only need to push the one directory that contains all the packages into the LOAD_PATH - I (think I) understand this. LOAD_PATH would be a directory containing each of the packages. So this is sufficient, rather than descending into each of them individually.

Exactly.

*** But again, that’s not recommended—it’s better to use the dev mechanism*** - fine, it seems we agree on this point? Better to avoid modifying JULIA_LOAD_PATH, JULIA_DEPOT_PATH and LOAD_PATH if possible?

Yes, in which case you are not using the Package Directory mechanism, you are putting the path to each dependency explicitly in each manifest that needs it.

Here’s the full layout of an example I generated:

MyProject:
Manifest.toml  PackageA/  PackageB/  Project.toml

MyProject/PackageA:
Manifest.toml Project.toml  src/

MyProject/PackageA/src:
PackageA.jl

MyProject/PackageB:
Manifest.toml  Project.toml  src/

MyProject/PackageB/src:
PackageB.jl

Example contents of various project and manifest files…

MyProject/Project.toml:

[deps]
PackageA = "2556dfe6-fba1-45c8-ae61-24ec43e93209"
PackageB = "f533fac8-037c-4ec8-a4c3-8f0aa0ff58a3"

MyProject/Manifest.toml:

# This file is machine-generated - editing it directly is not advised

julia_version = "1.11.2"
manifest_format = "2.0"
project_hash = "bd82cac20d9e29e79f49f82e3d4d848b38c6d981"

[[deps.PackageA]]
path = "PackageA"
uuid = "2556dfe6-fba1-45c8-ae61-24ec43e93209"
version = "0.1.0"

[[deps.PackageB]]
path = "PackageB"
uuid = "f533fac8-037c-4ec8-a4c3-8f0aa0ff58a3"
version = "0.1.0"

MyProject/PackageA/Project.toml:

name = "PackageA"
uuid = "2556dfe6-fba1-45c8-ae61-24ec43e93209"
authors = ["Stefan Karpinski <stefan@karpinski.org>"]
version = "0.1.0"

MyProject/PackageA/Manifest.toml:

# This file is machine-generated - editing it directly is not advised

julia_version = "1.11.2"
manifest_format = "2.0"
project_hash = "da39a3ee5e6b4b0d3255bfef95601890afd80709"

[deps]

MyProject/PackageB/Project.toml:

name = "PackageB"
uuid = "f533fac8-037c-4ec8-a4c3-8f0aa0ff58a3"
authors = ["Stefan Karpinski <stefan@karpinski.org>"]
version = "0.1.0"

[deps]
PackageA = "2556dfe6-fba1-45c8-ae61-24ec43e93209"

MyProject/PackageB/Manifest.toml:

# This file is machine-generated - editing it directly is not advised

julia_version = "1.11.2"
manifest_format = "2.0"
project_hash = "6d002591c1ced36dadf9d723d3ad71052e50f18d"

[[deps.PackageA]]
path = "../PackageA"
uuid = "2556dfe6-fba1-45c8-ae61-24ec43e93209"
version = "0.1.0"