[Agda] [ANNOUNCE] Agda 2.6.4.1 release candidate 2

[Andreas Abel]

Dear all,

greetings from the Agda Implementor's Meeting AIM XXXVII in Taipei!
The Agda Team is pleased to announce a 2nd release candidate for Agda 
2.6.4.1.

Fix in RC2 over RC1:

- Restore support for Emacs 26
   https://github.com/agda/agda/pull/7007

Agda 2.6.4.1 is a minor release of Agda 2.6.4 featuring a few changes:

- Make recursion on proofs legal again (regression in 2.6.4).
- Improve performance, e.g. by removing debug printing unless built with 
cabal flag `debug`.
- Switch to XDG directory convention.
- Reflection: change to order of results returned by `getInstances`.
- Fix some internal errors.
- Fix some issues with `opaque`.

# GHC supported versions

Agda 2.6.4.1 has been tested with GHC 9.8.1, GHC 9.6.3, 9.4.7, 9.2.8, 
9.0.2, 8.10.7, 8.8.4 and 8.6.5 on Linux, macOS and Windows.

# Installation

Agda 2.6.4.1 RC can be installed using cabal-install or stack:

1. Getting the release candidate

       $ cabal get 
https://hackage.haskell.org/package/Agda-2.6.4.1/candidate/Agda-2.6.4.1.tar.gz
       $ cd Agda-2.6.4.1

2. a. Using cabal-install

       $ cabal install -f +optimise-heavily -f +enable-cluster-counting

2. b. Using stack

       $ stack --stack-yaml stack-a.b.c.yaml install --flag 
Agda:optimise-heavily --flag Agda:enable-cluster-counting

replacing `a.b.c` with your version of GHC.

The flags mean:

   - optimise-heavily:
     Turn on extra optimisation for a faster Agda.
     Takes large resources during compilation of Agda.

   - enable-cluster-counting:
     Enable unicode clusters for alignment in the LaTeX backend.
     Requires the ICU lib to be installed and known to pkg-config.

These flags can be dropped from the install if causing trouble.

# Standard library

You can use standard library v1.7.3 or the `master` branch of the
standard library with Agda 2.6.4.1.  This branch is available at

   https://github.com/agda/agda-stdlib/

# Fixed issues over Agda 2.6.4

   https://hackage.haskell.org/package/Agda-2.6.4.1/candidate/changelog

Enjoy the Agda 2.6.4.1 RC and please test as much as possible.
Report problems and regressions to: https://github.com/agda/agda/issues

Andreas, on behalf of the Agda Team

-- 
Andreas Abel  <><      Du bist der geliebte Mensch.

Department of Computer Science and Engineering
Chalmers and Gothenburg University, Sweden

andreas.abel at gu.se
http://www.cse.chalmers.se/~abela/