fix: only pnpm install should fail on peer dep issues (#4596)

close #4577

.changeset/slow-laws-cheat.md

@@ -0,0 +1,5 @@
+---
+"@pnpm/core": patch
+---
+
+Only `pnpm install` should fail on peer dependency issues.

packages/core/src/install/index.ts

@@ -164,6 +164,7 @@ export async function mutateModules (
   }
 
   const installsOnly = projects.every((project) => project.mutation === 'install')
+  if (!installsOnly) opts.strictPeerDependencies = false
   opts['forceNewModules'] = installsOnly
   const rootProjectManifest = projects.find(({ rootDir }) => rootDir === opts.lockfileDir)?.manifest ??
     // When running install/update on a subset of projects, the root project might not be included,

packages/core/test/install/peerDependencies.ts

@@ -198,7 +198,11 @@ test('strict-peer-dependencies: error is thrown when cannot resolve peer depende
 
   let err!: PeerDependencyIssuesError
   try {
-    await addDependenciesToPackage({}, ['ajv-keywords@1.5.0'], await testDefaults({ strictPeerDependencies: true }))
+    await install({
+      dependencies: {
+        'ajv-keywords': '1.5.0',
+      },
+    }, await testDefaults({ strictPeerDependencies: true }))
   } catch (_err: any) { // eslint-disable-line
     err = _err
   }
@@ -322,7 +326,12 @@ test('strict-peer-dependencies: error is thrown when bad version of resolved pee
 
   let err!: PeerDependencyIssuesError
   try {
-    await addDependenciesToPackage({}, ['abc-grand-parent-without-c', 'peer-c@2'], await testDefaults({ strictPeerDependencies: true }))
+    await install({
+      dependencies: {
+        'abc-grand-parent-without-c': '1.0.0',
+        'peer-c': '2',
+      },
+    }, await testDefaults({ strictPeerDependencies: true }))
   } catch (_err: any) { // eslint-disable-line
     err = _err
   }