A new field in dependenciesMeta - linkBin

accepted/0000-link-bin.md

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+- Start Date: 2019-07-30
+- RFC PR: (leave this empty)
+- Yarn Issue: (leave this empty)
+
+# Summary
+
+The new `dependenciesMeta[dependency name].linkBin` field allows to prevent a dependency from
+linking its bin files to `node_modules/.bin`.
+
+# Motivation
+
+Sometimes several dependencies are exporting bin files that have the same name.
+For instance, both `gulp` and `gulp-cli` implement the `gulp` command.
+Which dependency's command should be linked into `node_modules/.bin`?
+There is currently no way to choose which dependency's command will be linked,
+when there's a conflict.
+
+# Detailed design
+
+Yarn already has a `dependenciesMeta` field. We can add a new field called `linkBin`.
+When `linkBin` will be `false`, the dependency's commands will be not linked.
+For instance:
+
+```json
+{
+  "dependencies": {
+    "gulp": "4.0.0",
+    "gulp-cli": "2.2.0"
+  },
+  "dependenciesMeta": {
+    "gulp": {
+      "linkBin": false
+    }
+  }
+}
+```
+
+# How We Teach This
+
+During a bin name conflict, Yarn may print a warning and suggest users to
+declare a dependenciesMeta field with `linkBin: false` for one of the conflicting dependencies.
+
+# Drawbacks
+
+# Alternatives
+
+# Unresolved questions
+
+The suggested solution might be not flexible enough.
+
+Should it be possible to disable specific commands only?
+Should it be possible to rename commands?