Workaround to not build cardano-lmdb but still resolve

Author: palas

flake.nix

@@ -142,6 +142,11 @@
             "https://chap.intersectmbo.org/" = inputs.CHaP;
           };
           # Also currently needed to make `nix flake lock --update-input CHaP` work.
+          # Disable --enable-tests in the plan so the solver doesn't
+          # resolve test-only dependencies of all packages (e.g.
+          # ouroboros-consensus:lmdb → cardano-lmdb). tests: True in
+          # cabal.project still enables tests for local packages.
+          configureArgs = "--disable-tests --disable-benchmarks";
           cabalProjectLocal = ''
             repository cardano-haskell-packages-local
               url: file:${inputs.CHaP}
@@ -153,10 +158,6 @@
             # Packages in this repo
             p.cardano-api
             p.cardano-api-gen
-            # Work around for issue created by our inability to register sublibs.
-            # This package may need to be built and we need to make sure its dependencies
-            # are included in `ghc-pkg list` (in particular `compact`)
-            p.ouroboros-consensus
           ];
           # tools we want in our shell, from hackage
           shell.tools =
@@ -294,6 +295,19 @@
                 src = nixpkgs.blst.src;
               });
           };
+          # Stub pkg-config file so the cabal solver can resolve
+          # cardano-lmdb (a transitive dependency of ouroboros-consensus
+          # that nothing in this project actually needs). Without this,
+          # the solver rejects cardano-lmdb because lmdb is not
+          # available for wasm. Per-component builds ensure it is never
+          # actually compiled.
+          lmdb-pkg-config-stub = wasm-pkgs.writeTextDir "lib/pkgconfig/lmdb.pc" ''
+            Name: lmdb
+            Description: Stub for cabal solver — not actually built
+            Version: 0.9.33
+            Libs: -llmdb
+            Cflags:
+          '';
         in
           lib.optionalAttrs (system != "x86_64-darwin") {
             wasm = wasm-pkgs.mkShell {
@@ -308,6 +322,7 @@
                   wasm.libsodium
                   wasm.secp256k1
                   wasm.blst
+                  lmdb-pkg-config-stub
                 ]
                 ++ lib.optional (system == "x86_64-linux" || system == "aarch64-linux") wasm-pkgs.envoy-bin;
             };