Merge branch 'release-3.4.0' into language-reference-stable

.github/ISSUE_TEMPLATE/crash.md

@@ -25,6 +25,9 @@ println("hello, world")
 ```
 
 ## Output (click arrow to expand)
+<!--
+Note: to get a full crash log when using scala-cli, run compilation with the flag `--server=false`
+-->
 <details>
 
 ```scala

.github/ISSUE_TEMPLATE/feature.md

@@ -1,10 +1,10 @@
 ---
 name: "\U0001F389 Suggest a feature"
-about: Please create a feature request here https://github.com/lampepfl/dotty-feature-requests
+about: Please create a feature request here https://github.com/lampepfl/dotty/discussions/new?category=feature-requests
 title: ''
 labels: ''
 assignees: ''
 
 ---
 
-Please create a feature request here: [lampepfl/dotty-feature-requests](https://github.com/lampepfl/dotty-feature-requests).
+Please create a feature request in the [Dotty Discussions](https://github.com/lampepfl/dotty/discussions/new?category=feature-requests).

.github/ISSUE_TEMPLATE/improve-error.md

@@ -0,0 +1,55 @@
+---
+name: "\U0001F615 Error/Warning message report"
+about: Report an error/warning message that was confusing/unhelpful
+title: ''
+labels: itype:enhancement, area:reporting, better-errors, stat:needs triage
+assignees: ''
+
+---
+
+## Compiler version
+
+If you're not sure what version you're using, run `print scalaVersion` from sbt
+(if you're running scalac manually, use `scalac -version` instead).
+
+## Minimized example
+
+<!--
+This code should be self-contained, reproducible (i.e. produces the expected error/warning message) and as small as possible.
+
+Ideally, we should be able to just copy this code in a file and run `scalac` (and maybe `scala`) to reproduce the issue.
+
+For a good example, see https://github.com/lampepfl/dotty/issues/18657
+-->
+
+```Scala
+printl("hello, world")
+```
+
+## Output Error/Warning message
+
+<!--
+Here, please provide the produced error/warning message that is confusing/unhelpful, etc.
+
+for example:
+-->
+
+```scala
+-- [E006] Not Found Error: ----------------
+1 |printl("hello, world")
+  |^^^^^^
+  |Not found: printl
+1 error found
+```
+
+## Why this Error/Warning was not helpful
+
+<!-- For a good example, see https://github.com/lampepfl/dotty/issues/18657 -->
+
+The message was unhelpful because...
+
+## Suggested improvement
+
+<!-- For a good example, see https://github.com/lampepfl/dotty/issues/18657 -->
+
+It could be made more helpful by...

.github/workflows/ci.yaml

@@ -18,6 +18,8 @@ on:
       - '*'
     branches-ignore:
       - 'gh-readonly-queue/**'
+      - 'release-**'
+      - 'lts-**'
   pull_request:
   merge_group:
   schedule:
@@ -70,13 +72,13 @@ jobs:
         run: git -c "http.https://github.com/.extraheader=" fetch --recurse-submodules=no "https://github.com/lampepfl/dotty" && git reset --hard FETCH_HEAD || true
 
       - name: Checkout cleanup script
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Cleanup
         run: .github/workflows/cleanup.sh
 
       - name: Git Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Add SBT proxy repositories
         run: cp -vf .github/workflows/repositories /root/.sbt/ ; true
@@ -121,27 +123,72 @@ jobs:
         run: git -c "http.https://github.com/.extraheader=" fetch --recurse-submodules=no "https://github.com/lampepfl/dotty" && git reset --hard FETCH_HEAD || true
 
       - name: Checkout cleanup script
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Cleanup
         run: .github/workflows/cleanup.sh
 
       - name: Git Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Add SBT proxy repositories
         run: cp -vf .github/workflows/repositories /root/.sbt/ ; true
 
       - name: Cmd Tests
         run: |
-          ./project/scripts/sbt ";dist/pack; scala3-bootstrapped/compile; scala3-bootstrapped/test ;sbt-test/scripted scala2-compat/* ;stdlib-bootstrapped/test:run ;stdlib-bootstrapped-tasty-tests/test; scala3-compiler-bootstrapped/scala3CompilerCoursierTest:test"
+          ./project/scripts/sbt ";dist/pack; scala3-bootstrapped/compile; scala3-bootstrapped/test ;sbt-test/scripted scala2-compat/* ;scala2-library-tasty-tests/run ;scala2-library-tasty-tests/test; scala3-compiler-bootstrapped/scala3CompilerCoursierTest:test"
           ./project/scripts/cmdTests
           ./project/scripts/bootstrappedOnlyCmdTests
 
       - name: Scala.js Test
         run: |
           ./project/scripts/sbt ";sjsSandbox/run ;sjsSandbox/test ;sjsJUnitTests/test ;set sjsJUnitTests/scalaJSLinkerConfig ~= switchToESModules ;sjsJUnitTests/test ;sjsCompilerTests/test"
 
+      - name: Test with Scala 2 library TASTy (fast)
+        run: ./project/scripts/sbt ";set ThisBuild/Build.useScala2LibraryTasty := true ;scala3-bootstrapped/testCompilation i5; scala3-bootstrapped/testCompilation tests/run/typelevel-peano.scala; scala3-bootstrapped/testOnly dotty.tools.backend.jvm.DottyBytecodeTests" # only test a subset of test to avoid doubling the CI execution time
+
+  test_scala2_library_tasty:
+    runs-on: [self-hosted, Linux]
+    container:
+      image: lampepfl/dotty:2021-03-22
+      options: --cpu-shares 4096
+      volumes:
+        - ${{ github.workspace }}/../../cache/sbt:/root/.sbt
+        - ${{ github.workspace }}/../../cache/ivy:/root/.ivy2/cache
+        - ${{ github.workspace }}/../../cache/general:/root/.cache
+    if: "github.event_name == 'schedule' && github.repository == 'lampepfl/dotty'
+         || (
+           github.event_name == 'pull_request'
+           && contains(github.event.pull_request.body, '[test_scala2_library_tasty]')
+         )
+         || (
+           github.event_name == 'workflow_dispatch'
+           && github.repository == 'lampepfl/dotty'
+         )"
+
+    steps:
+      - name: Set JDK 16 as default
+        run: echo "/usr/lib/jvm/java-16-openjdk-amd64/bin" >> $GITHUB_PATH
+
+      - name: Reset existing repo
+        run: git -c "http.https://github.com/.extraheader=" fetch --recurse-submodules=no "https://github.com/lampepfl/dotty" && git reset --hard FETCH_HEAD || true
+
+      - name: Checkout cleanup script
+        uses: actions/checkout@v4
+
+      - name: Cleanup
+        run: .github/workflows/cleanup.sh
+
+      - name: Git Checkout
+        uses: actions/checkout@v4
+
+      - name: Add SBT proxy repositories
+        run: cp -vf .github/workflows/repositories /root/.sbt/ ; true
+
+      - name: Test with Scala 2 library TASTy
+        run: ./project/scripts/sbt ";set ThisBuild/Build.useScala2LibraryTasty := true ;scala3-bootstrapped/test"
+
+
   test_windows_fast:
     runs-on: [self-hosted, Windows]
     if: "(
@@ -161,7 +208,7 @@ jobs:
         shell: cmd
 
       - name: Git Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Test
         run: sbt ";scala3-bootstrapped/compile"
@@ -203,7 +250,7 @@ jobs:
         shell: cmd
 
       - name: Git Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Test
         run: sbt ";dist/pack ;scala3-bootstrapped/compile ;scala3-bootstrapped/test"
@@ -240,20 +287,25 @@ jobs:
         run: git -c "http.https://github.com/.extraheader=" fetch --recurse-submodules=no "https://github.com/lampepfl/dotty" && git reset --hard FETCH_HEAD || true
 
       - name: Checkout cleanup script
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Cleanup
         run: .github/workflows/cleanup.sh
 
       - name: Git Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Add SBT proxy repositories
         run: cp -vf .github/workflows/repositories /root/.sbt/ ; true
 
       - name: MiMa
         run: |
-          ./project/scripts/sbt ";scala3-interfaces/mimaReportBinaryIssues ;scala3-library-bootstrapped/mimaReportBinaryIssues ;scala3-library-bootstrappedJS/mimaReportBinaryIssues; tasty-core-bootstrapped/mimaReportBinaryIssues"
+          ./project/scripts/sbt ";scala3-interfaces/mimaReportBinaryIssues ;scala3-library-bootstrapped/mimaReportBinaryIssues ;scala3-library-bootstrappedJS/mimaReportBinaryIssues; tasty-core-bootstrapped/mimaReportBinaryIssues; scala2-library-bootstrapped/mimaReportBinaryIssues"
+
+      - name: TASTy MiMa
+        run: |
+          # This script cleans the compiler and recompiles it from scratch (keep as last run)
+          ./project/scripts/scala2-library-tasty-mima.sh
 
   community_build_a:
     runs-on: [self-hosted, Linux]
@@ -283,13 +335,13 @@ jobs:
         run: git -c "http.https://github.com/.extraheader=" fetch --recurse-submodules=no "https://github.com/lampepfl/dotty" && git reset --hard FETCH_HEAD || true
 
       - name: Checkout cleanup script
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Cleanup
         run: .github/workflows/cleanup.sh
 
       - name: Git Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Add SBT proxy repositories
         run: cp -vf .github/workflows/repositories /root/.sbt/ ; true
@@ -332,13 +384,13 @@ jobs:
         run: git -c "http.https://github.com/.extraheader=" fetch --recurse-submodules=no "https://github.com/lampepfl/dotty" && git reset --hard FETCH_HEAD || true
 
       - name: Checkout cleanup script
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Cleanup
         run: .github/workflows/cleanup.sh
 
       - name: Git Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Add SBT proxy repositories
         run: cp -vf .github/workflows/repositories /root/.sbt/ ; true
@@ -381,13 +433,13 @@ jobs:
         run: git -c "http.https://github.com/.extraheader=" fetch --recurse-submodules=no "https://github.com/lampepfl/dotty" && git reset --hard FETCH_HEAD || true
 
       - name: Checkout cleanup script
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Cleanup
         run: .github/workflows/cleanup.sh
 
       - name: Git Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Add SBT proxy repositories
         run: cp -vf .github/workflows/repositories /root/.sbt/ ; true
@@ -428,13 +480,13 @@ jobs:
         run: git -c "http.https://github.com/.extraheader=" fetch --recurse-submodules=no "https://github.com/lampepfl/dotty" && git reset --hard FETCH_HEAD || true
 
       - name: Checkout cleanup script
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Cleanup
         run: .github/workflows/cleanup.sh
 
       - name: Git Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Add SBT proxy repositories
         run: cp -vf .github/workflows/repositories /root/.sbt/ ; true
@@ -475,20 +527,20 @@ jobs:
         run: git -c "http.https://github.com/.extraheader=" fetch --recurse-submodules=no "https://github.com/lampepfl/dotty" && git reset --hard FETCH_HEAD || true
 
       - name: Checkout cleanup script
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Cleanup
         run: .github/workflows/cleanup.sh
 
       - name: Git Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Add SBT proxy repositories
         run: cp -vf .github/workflows/repositories /root/.sbt/ ; true
 
       - name: Test
         run: |
-          ./project/scripts/sbt ";dist/pack ;scala3-bootstrapped/compile ;scala3-bootstrapped/test ;sbt-test/scripted scala2-compat/* ;stdlib-bootstrapped/test:run ;stdlib-bootstrapped-tasty-tests/test"
+          ./project/scripts/sbt ";dist/pack ;scala3-bootstrapped/compile ;scala3-bootstrapped/test ;sbt-test/scripted scala2-compat/* ;scala2-library-tasty-tests/run ;scala2-library-tasty-tests/test"
           ./project/scripts/cmdTests
           ./project/scripts/bootstrappedOnlyCmdTests
 
@@ -519,13 +571,13 @@ jobs:
         run: git -c "http.https://github.com/.extraheader=" fetch --recurse-submodules=no "https://github.com/lampepfl/dotty" && git reset --hard FETCH_HEAD || true
 
       - name: Checkout cleanup script
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Cleanup
         run: .github/workflows/cleanup.sh
 
       - name: Git Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Add SBT proxy repositories
         run: cp -vf .github/workflows/repositories /root/.sbt/ ; true
@@ -573,13 +625,13 @@ jobs:
         run: git -c "http.https://github.com/.extraheader=" fetch --recurse-submodules=no "https://github.com/lampepfl/dotty" && git reset --hard FETCH_HEAD || true
 
       - name: Checkout cleanup script
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Cleanup
         run: .github/workflows/cleanup.sh
 
       - name: Git Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Add SBT proxy repositories
         run: cp -vf .github/workflows/repositories /root/.sbt/ ; true
@@ -623,13 +675,13 @@ jobs:
         run: git -c "http.https://github.com/.extraheader=" fetch --recurse-submodules=no "https://github.com/lampepfl/dotty" && git reset --hard FETCH_HEAD || true
 
       - name: Checkout cleanup script
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Cleanup
         run: .github/workflows/cleanup.sh
 
       - name: Git Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Add SBT proxy repositories
         run: cp -vf .github/workflows/repositories /root/.sbt/ ; true
@@ -696,7 +748,7 @@ jobs:
     if: "failure() && github.event_name == 'schedule'"
     steps:
       - name: Checkout issue template
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Open an issue
         uses: JasonEtco/create-an-issue@v2

.github/workflows/cla.yml

@@ -15,7 +15,7 @@ jobs:
   check:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@v4
     - run: ./project/scripts/check-cla.sh
       if: github.event_name == 'pull_request'
       env:

.github/workflows/dependency-graph.yml

@@ -8,5 +8,5 @@ jobs:
     name: Update Dependency Graph
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - uses: scalacenter/sbt-dependency-submission@v2