Using nightly Rust is problematic

[jnalanko]

The build was again broken on latest nightly. It seems to be fixed now, but to prevent future breakage, I think it would be better if GGCAT used a fixed Rust version that is not the nightly version.

[rob-p]

I was talking with @jermp about this. Might I ask what nightly features are required in GGCAT? In general, nightly is highly unstable (some features on nightly might never make it into stable and, in fact, might be removed completely). Depending on beta or stable would be much more robust if there are only features being used that could be replaced by some macros or crates that work on stable.

[Guilucand]

Hi, the nightly features I currently use on GGCAT are these:

#![feature(const_type_id)]
#![feature(drain_filter)]
#![feature(int_roundings)]
#![feature(let_chains)]
#![feature(new_uninit)]
#![feature(panic_info_message)]
#![feature(slice_group_by)]
#![feature(slice_partition_dedup)]
#![feature(thread_local)]

#![feature(impl_trait_in_assoc_type)]

I think almost all of them can be removed by implementing the features in a separate library, But the impl_trait_in_assoc_type feature is very handy and cannot be easily replaced by something else, since simple alternatives usually add an extra layer of indirection that could affect the performance.

In the next days I'll try to remove as much unstable features as possible, and see if I can also find a workaround for the last one.

[jermp]

Hi, Actually I tried to remove the

![feature(impl_trait_in_assoc_type)]

and everything went smooth with the stable channel release.

[leoisl]

Hello, thanks a lot for this tool, I'd like to experiment querying plasmids and AMR genes against the 661k bacterial dataset with it. I am having the same issue but I do not know rust, sorry. I get this error when trying to install in my cluster:

   Compiling ggcat_kmers_transform v0.1.0 (~/ggcat/crates/kmers_transform)
error[E0635]: unknown feature `drain_filter`
 --> crates/kmers_transform/src/lib.rs:2:12
  |
2 | #![feature(drain_filter)]
  |            ^^^^^^^^^^^^

   Compiling ggcat_assembler_minimizer_bucketing v0.1.0 (~/ggcat/crates/assembler_minimizer_bucketing)
For more information about this error, try `rustc --explain E0635`.
error: could not compile `ggcat_kmers_transform` (lib) due to previous error
warning: build failed, waiting for other jobs to finish...
error: failed to compile `ggcat_cmdline v0.1.0 (~/ggcat/crates/cmdline)`, intermediate artifacts can be found at `~/ggcat/target`.

... should I keep trying from time to time until there is a nightly version that does not break?

[rob-p]

What is your current rustc version?

[Guilucand]

Hi, I worked on the removal of the nightly features, and now only three of them remain:

#![feature(impl_trait_in_assoc_type)]
#![feature(thread_local)]
#![feature(slice_partition_dedup)]

The updated code (that should compile on a wider range of nightly rust versions) is available in the dev branch

[sebschmi]

Nowadays, you can use the rust-toolchain.toml to pin to the nightly version of a certain date.

Modified example from the docs:

[toolchain]
channel = "nightly-2023-09-07"

[Guilucand]

Good news, with the stabilization of the feature return_position_impl_trait_in_trait in Rust 1.75 GGCAT now uses no unstable features.

The final transition to stable Rust is still blocked by a small change that needs to be made to the matchtigs library, for which I just made a pull request.

[rob-p]

RPITIT FTW! Yay acronyms.

[jermp]

Great! Keep us posted :)

[Guilucand]

I managed to support stable even without the matchtigs library fix, so now GGCAT works on stable Rust >= 1.75 :)