Better detection of RHEL 9.x for GHC >= 9.6

[pierreMizrahi]

Hi,

on RHEL 9.2, by default ghcup downloads the centos7 version, which uses libtinfo5. This works well during the install, but the ghc version is unusable, for example:

$ ghcup install ghc --force 9.6.4
$ ghc --version
/home/pierre.mizrahi/.ghcup/ghc/9.6.4/lib/ghc-9.6.4/bin/./ghc-9.6.4: error while loading shared libraries: libtinfo.so.5: cannot open shared object file: No such file or directory

A better match would be to use Fedora 33 (RHEL 9.2 is alike Fedora 34, see https://docs.fedoraproject.org/en-US/quick-docs/fedora-and-red-hat-enterprise-linux/):

$ ghcup -p x86_64-fedora33-linux install ghc --force 9.6.4
$ ghc --version
The Glorious Glasgow Haskell Compilation System, version 9.6.4

Debug info:

$ ghcup debug-info
Debug Info
==========
GHCup base dir: /home/pierre.mizrahi/.ghcup
GHCup bin dir: /home/pierre.mizrahi/.ghcup/bin
GHCup GHC directory: /home/pierre.mizrahi/.ghcup/ghc
GHCup cache directory: /home/pierre.mizrahi/.ghcup/cache
Architecture: x86_64
Platform: Linux RedHat, 9.2
Version: 0.1.20.0

[hasufell]

The problem is we can't test RHEL in CI. And I don't have one.

[pierreMizrahi]

Fair enough, and thanks for the answer.

While specifying the platform override works for me, many enterprise users are using RHEL and this arguably could harm adoption there.

(There is a no cost version of RHEL available here : https://developers.redhat.com/products/rhel/download

What do you think about mapping from RHEL to Fedora or Rocky using the official table, and only test the community supported equivalent ? that probably won't be perfect, but that would be no worse than currently, and platform overrides can still be used for the edge cases.

Alternatively, one could add a specific section in the readme. Would you like me to do a PR ?

[hasufell]

There is a no cost version of RHEL available here : https://developers.redhat.com/products/rhel/download

Do they provide docker containers?

[juhp]

Maybe you can use registry.access.redhat.com/ubi9/ubi

See https://catalog.redhat.com/software/base-images

Or the CentOS stream 9 image might be easier

[pierreMizrahi]

some more doc: https://developers.redhat.com/blog/2020/03/24/red-hat-universal-base-images-for-docker-users#

(disclaimer, I am not a docker user)

[josephcsible]

Alma, Rocky, and Oracle Linux 9 are all freely available and binary compatible with RHEL 9.