Add windows-secp256k1 binary distribution (#1424)

Author: hamishmack

.github/workflows/windows-secp256k1.yml

@@ -0,0 +1,50 @@
+name: "Test secp256k1 on windows"
+on: workflow_dispatch
+jobs:
+  tests:
+    runs-on: windows-latest
+
+    defaults:
+      run:
+        shell: bash
+
+    steps:
+
+    - uses: haskell/actions/setup@v1
+      id: setup-haskell
+      with:
+        ghc-version: 8.10.7
+        cabal-version: 3.6.2.0
+     
+    - name: Install pkgconfiglite
+      run: choco install -y pkgconfiglite
+
+    - name: Install libsecp256k1
+      run: |
+        curl -Ls \
+          --connect-timeout 5 \
+          --max-time 10 \
+          --retry 5 \
+          --retry-delay 0 \
+          --retry-max-time 40 \
+          https://hydra.iohk.io/job/Cardano/haskell-nix/windows-secp256k1/latest/download/1 -o secp256k1.zip
+        mkdir secp256k1
+        cd secp256k1
+        unzip ../secp256k1.zip
+        cd ..
+        export PKG_CONFIG_PATH="$(readlink -f secp256k1/lib/pkgconfig)"
+        echo "PKG_CONFIG_PATH=$PKG_CONFIG_PATH" >> $GITHUB_ENV
+        export SECP256K1_PATH="$(readlink -f secp256k1/bin | tr / '\\')"
+        echo "$SECP256K1_PATH" >> $GITHUB_PATH
+
+    - name: Cabal update
+      run: cabal update
+
+    - name: Build and run haskell-secp256k1 tests
+      run: |
+        cabal unpack secp256k1-haskell
+        cd secp256k1-haskell-*
+        cabal build --enable-tests
+        cp ../secp256k1/bin/*.dll dist-newstyle/build/x86_64-windows/ghc-*/secp256k1-haskell-*/t/spec/build/spec/
+        cabal test
+

release.nix

@@ -46,6 +46,19 @@ let
         ) (names nixpkgsJobs)
       ) (names allJobs));
 in traceNames "job " (latestJobs // requiredJobs // {
+    windows-secp256k1 =
+      let
+        pkgs = (import ./. {}).pkgs-unstable; 
+        makeBinDist = drv: pkgs.runCommand drv.name {
+          nativeBuildInputs = [ pkgs.zip ];
+        } ''
+          mkdir -p $out/nix-support
+          cp -r ${drv}/* .
+          chmod -R +w .
+          zip -r $out/${drv.name}.zip .
+          echo "file binary-dist $out/${drv.name}.zip" > $out/nix-support/hydra-build-products
+       '';
+      in makeBinDist pkgs.pkgsCross.mingwW64.secp256k1;
     required = genericPkgs.releaseTools.aggregate {
       name = "haskell.nix-required";
       meta.description = "All jobs required to pass CI";