nim CI broken: eth2_vectors.nim(17, 3) Error: cannot open file: yaml about nim-blscurve

[mratsim]

1. For testing, blscurve now requires NimYAML, it's not a package dependency so I did not list it in the .nimble file
2. In the CI setup it has been added as via a nimble install https://github.com/status-im/NimYAML@#head preceding nimble test
3. To make matter worse, the original yaml package was broken by YAML upstream deleting a commit that prevents git submodule update to work in nimYAML flyx/NimYAML#77. This means that requiring the yaml package will also trigger failures
4. AFAIK we can't do requires https://github.com/status-im/NimYAML@#head in a nimble file as a work-around
5. Nimble doesn't support task-level dependencies nim-lang/nimble#482

Plans forward:

• We can't wait for nimble features (i.e. requiring a repo path + branch and task-level dependencies)
• We can't wait for nimble install yaml to be fixed

So I recommend you disable blscurve and probably all packages that requires NimYAML in the Nim CI for the time being.

In the future (a week or so), once official test vectors are available (in json format) we will remove the dependency on the current YAML test vectors (cfrg/draft-irtf-cfrg-hash-to-curve#214)

[timotheecour]

• maybe send an issue to https://github.com/flyx/NimYAML/issues (and link here)?

AFAIK we can't do requires https://github.com/status-im/NimYAML@#head in a nimble file as a work-around

wouldn't that increase chances of mutually exclusive requirements, eg:

pkg1: 
requires https://github.com/status-im/NimYAML@#head
pkg2: 
requires https://github.com/status-im/NimYAML@#1234 # 
pkg3:
requires pkg1, pkg2

the alternative is:

• nimble develop https://github.com/status-im/NimYAML (or manually via git clone until nim-lang/nimble#577 is fixed)
• if needed checkout a specific hash
• proceed with installing other packages

in any case, that discussion should happen in https://github.com/nim-lang/nimble/issues otherwise will never be fixed; maybe open an issue there and link to here?

task-level dependencies
can then be achieved by (untested):
nimble install -d:with_foo mypkg

# mypkg.nimble:
when defined(with_foo):
  requires foo

[mratsim]

1. You probably missed flyx/NimYAML#77 in my post.
2. For the mutually exclusive requirements, it should be discussed in the lock files issue: nim-lang/nimble#127. Being unable to install pkg3 due to conflicting requirements is not a bug.

• We can also requires that a minimal commit or a maximum commit in the package for more flexibitlity but targeting a specific commit seems like a nice start.
• Alternatively, Rust can somehow handle multiple conflicting requirements in the same codebase, including versions of the Rust compiler. But AFAIK that would require a lot of plumbing on Nim side to be able to do the same.

3. Using nimble install -d:with_foo mypkg is not really an improvement over nimble install yaml mypkg for testing. Both require to be aware of specific testing dependencies.