From 55989d7ac8a3650a084d82dc65f75c6aa2a36554 Mon Sep 17 00:00:00 2001
From: jaschutte <34577095+jaschutte@users.noreply.github.com>
Date: Mon, 4 Aug 2025 09:54:15 +0000
Subject: [PATCH] Expose all supported GHC versions (#2987)

Right now the only default GHC version gets exported by the flake. This
means that libraries wanting to use the clash-compiler flake
realistically can only support the default GHC version. If someone wants
to use any of the other supported versions, that would work fine for
clash-compiler, but it wouldn't trickle down to the libraries (which are
stuck with the default ghc version).

Graphs visualizing the issue:

If you want to develop with the default version (ghc9101)
```
myprogram => ghc9101
 |- clash-compiler => ghc9101
 \- clash-protocols => ghc9101
     |- clash-compiler => ghc9101
     \- circuit-notation => ghc9101
         \- clash-compiler => ghc9101
```

With a non-default, but supported version (ghc964)
```
myprogram => ghc964
 |- clash-compiler => ghc964
 \- clash-protocols => ghc9101
     |- clash-compiler => ghc9101
     \- circuit-notation => ghc9101
         \- clash-compiler => ghc9101
```

(cherry picked from commit 6a0810496560e2ff2a0071f315afb573c12bba39)
---
 flake.nix | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/flake.nix b/flake.nix
index c6f6284112..012806b7b2 100644
--- a/flake.nix
+++ b/flake.nix
@@ -83,6 +83,10 @@
       in
       assert pkgs.lib.asserts.assertOneOf "defaultGhcVersion" defaultGhcVersion ghcVersions;
       {
+        # Export the variable so that other flakes can use it.
+        ghcVersion = defaultGhcVersion;
+        supportedGhcVersions = ghcVersions;
+
         packages = {
           inherit (pkgs."clashPackages-${defaultGhcVersion}")
             clash-benchmark