Fixes pack when a workspace dependency has no version (#2479)

* Uses 0.0.0 when no workspace version is configured

* Adds versions

.yarn/versions/08c52146.yml

@@ -0,0 +1,23 @@
+releases:
+  "@yarnpkg/cli": patch
+  "@yarnpkg/plugin-pack": patch
+
+declined:
+  - "@yarnpkg/plugin-compat"
+  - "@yarnpkg/plugin-constraints"
+  - "@yarnpkg/plugin-dlx"
+  - "@yarnpkg/plugin-essentials"
+  - "@yarnpkg/plugin-init"
+  - "@yarnpkg/plugin-interactive-tools"
+  - "@yarnpkg/plugin-node-modules"
+  - "@yarnpkg/plugin-npm"
+  - "@yarnpkg/plugin-npm-cli"
+  - "@yarnpkg/plugin-patch"
+  - "@yarnpkg/plugin-pnp"
+  - "@yarnpkg/plugin-stage"
+  - "@yarnpkg/plugin-typescript"
+  - "@yarnpkg/plugin-version"
+  - "@yarnpkg/plugin-workspace-tools"
+  - "@yarnpkg/builder"
+  - "@yarnpkg/core"
+  - "@yarnpkg/doctor"

packages/plugin-pack/sources/index.ts

@@ -54,12 +54,11 @@ const beforeWorkspacePacking = (workspace: Workspace, rawManifest: any) => {
 
         // For workspace:path/to/workspace and workspace:* we look up the workspace version
         if (structUtils.areDescriptorsEqual(descriptor, matchingWorkspace.anchoredDescriptor) || range.selector === `*`)
-          versionToWrite = matchingWorkspace.manifest.version!;
+          versionToWrite = matchingWorkspace.manifest.version ?? `0.0.0`;
         else
           // for workspace:version we simply strip the protocol
           versionToWrite = range.selector;
 
-
         rawManifest[dependencyType][structUtils.stringifyIdent(descriptor)] = versionToWrite;
       }
     }