Add ability to have a pin version

[littlejo]

What

This PR adds support for an optional pinned version (rev_version) for Aya crates
(aya, aya-build, aya-ebpf, aya-log, aya-log-ebpf) in the aya-template.

Why

Previously, the template always pointed to the main branch of the Aya repository.
As a result, cargo-generate could break when new commits in Aya changed the public API
(e.g., removal of cargo_metadata from aya-build).

With this change, users can optionally provide rev_version to pin the template
dependencies to a specific commit, making generated projects more stable and reproducible.

Example usage

cargo generate https://github.com/aya-rs/aya-template --name my-project -d rev_version=a18e283e2afd6b85511f6f180069410def79f473

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[vadorovsky]

I don't think this will work, even for the latest release. APIs can be incompatible across versions and we need to handle these differences. Supporting all versions, or even N > 1 versions, is too much work IMO. I would just stick to one stable version.

What I think would make sense is a parameter like release = ["stable", "git"] and guarding the API-incompatible code with {% if release == "stable" %} / {% if release == "git" %}. What do you think?

Also, we would need to test both options in CI.

[littlejo]

I don't think this will work, even for the latest release. APIs can be incompatible across versions and we need to handle these differences. Supporting all versions, or even N > 1 versions, is too much work IMO. I would just stick to one stable version.

What I think would make sense is a parameter like release = ["stable", "git"] and guarding the API-incompatible code with {% if release == "stable" %} / {% if release == "git" %}. What do you think?

Yes, you're probably right

[vadorovsky]

I don't think this will work, even for the latest release. APIs can be incompatible across versions and we need to handle these differences. Supporting all versions, or even N > 1 versions, is too much work IMO. I would just stick to one stable version.
What I think would make sense is a parameter like release = ["stable", "git"] and guarding the API-incompatible code with {% if release == "stable" %} / {% if release == "git" %}. What do you think?

Yes, you're probably right

Are you willing to give it a try? 🙂

[littlejo]

I don't think this will work, even for the latest release. APIs can be incompatible across versions and we need to handle these differences. Supporting all versions, or even N > 1 versions, is too much work IMO. I would just stick to one stable version.
What I think would make sense is a parameter like release = ["stable", "git"] and guarding the API-incompatible code with {% if release == "stable" %} / {% if release == "git" %}. What do you think?

Yes, you're probably right

Are you willing to give it a try? 🙂

I tested on another branch:

https://github.com/littlejo/aya-template/tree/stable-release3

But i have a lot of errors:

error[E0277]: the trait bound `EbpfLogger: AsRawFd` is not satisfied
   --> testaaa/src/main.rs:46:57
    |
 46 |                 tokio::io::unix::AsyncFd::with_interest(logger, tokio::io::Interest::READABLE)?;
    |                 --------------------------------------- ^^^^^^ the trait `AsRawFd` is not implemented for `EbpfLogger`
    |                 |
    |                 required by a bound introduced by this call
    |
    = help: the following other types implement trait `AsRawFd`:
              Arc<T>
              AsyncFd<T>
              BorrowedFd<'_>
              Box<T>
              ChildStderr
              ChildStdin
              ChildStdout
              File
            and 47 others
note: required by a bound in `AsyncFd::<T>::with_interest`
   --> /root/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/io/async_fd.rs:210:9
    |
210 | impl<T: AsRawFd> AsyncFd<T> {
    |         ^^^^^^^ required by this bound in `AsyncFd::<T>::with_interest`
...
243 |     pub fn with_interest(inner: T, interest: Interest) -> io::Result<Self>
    |            ------------- required by a bound in this associated function

error[E0277]: the trait bound `EbpfLogger: AsRawFd` is not satisfied
   --> testaaa/src/main.rs:46:17
    |
 46 |                 tokio::io::unix::AsyncFd::with_interest(logger, tokio::io::Interest::READABLE)?;
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `AsRawFd` is not implemented for `EbpfLogger`
    |
    = help: the following other types implement trait `AsRawFd`:
              Arc<T>
              AsyncFd<T>
              BorrowedFd<'_>
              Box<T>
              ChildStderr
              ChildStdin
              ChildStdout
              File
            and 47 others
note: required by a bound in `AsyncFd`
   --> /root/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/io/async_fd.rs:181:23
    |
181 | pub struct AsyncFd<T: AsRawFd> {
    |                       ^^^^^^^ required by this bound in `AsyncFd`

error[E0277]: the trait bound `EbpfLogger: AsRawFd` is not satisfied
   --> testaaa/src/main.rs:46:17
    |
 46 |                 tokio::io::unix::AsyncFd::with_interest(logger, tokio::io::Interest::READABLE)?;
    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `AsRawFd` is not implemented for `EbpfLogger`
    |
    = help: the following other types implement trait `AsRawFd`:
              Arc<T>
              AsyncFd<T>
              BorrowedFd<'_>
              Box<T>
              ChildStderr
              ChildStdin
              ChildStdout
              File
            and 47 others
note: required by a bound in `AsyncFd`
   --> /root/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/tokio-1.48.0/src/io/async_fd.rs:181:23
    |
181 | pub struct AsyncFd<T: AsRawFd> {
    |                       ^^^^^^^ required by this bound in `AsyncFd`

error[E0599]: the method `readable_mut` exists for struct `AsyncFd<EbpfLogger>`, but its trait bounds were not satisfied
  --> testaaa/src/main.rs:49:44
   |
49 |                     let mut guard = logger.readable_mut().await.unwrap();
   |                                            ^^^^^^^^^^^^ method cannot be called on `AsyncFd<EbpfLogger>` due to unsatisfied trait bounds
   |
  ::: /root/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/aya-log-0.2.1/src/lib.rs:97:1
   |
97 | pub struct EbpfLogger;
   | --------------------- doesn't satisfy `EbpfLogger: AsRawFd`
   |
   = note: the following trait bounds were not satisfied:
           `EbpfLogger: AsRawFd`

[provokateurin]

@littlejo I was hitting the same build failures as you (while trying to use the latest versions from crates.io) and managed to get it building by reverting these changes: 0158e1b

I would also appreciate a lot of the template was using exact specified versions instead of git dependencies.

[provokateurin]

@tamird would you please follow up on #152 (review)? 😅