ci: add fresh-install workflow for first-time user experience

.github/workflows/ci-fresh-install.yml

@@ -0,0 +1,161 @@
+name: ci-fresh-install
+
+# Fresh install CI — validates the released mcpp binary via xlings.
+# Simulates a real first-time user on a clean machine (no caches).
+#
+# For each platform, tests every supported toolchain:
+#   1. mcpp new hello → mcpp run (basic project)
+#   2. mcpp build (build mcpp itself from source)
+#
+# This workflow tests released mcpp, not PR code.
+# It does NOT run on PRs — only on push to main, manual trigger, and daily schedule.
+# Failures here mean the released mcpp has issues, not that the PR is broken.
+
+on:
+  push:
+    branches: [ main ]
+  workflow_dispatch:
+  schedule:
+    # Run daily at 06:00 UTC to catch issues from xlings/runner updates
+    - cron: '0 6 * * *'
+
+concurrency:
+  group: ci-fresh-install
+  cancel-in-progress: true
+
+jobs:
+  # ──────────────────────────────────────────────────────────────────
+  # Linux: gcc@16.1.0, musl-gcc@15.1.0, llvm@20.1.7
+  # ──────────────────────────────────────────────────────────────────
+  linux-fresh:
+    name: Linux fresh install
+    runs-on: ubuntu-24.04
+    timeout-minutes: 60
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install xlings + mcpp
+        env:
+          XLINGS_NON_INTERACTIVE: '1'
+        run: |
+          curl -fsSL https://github.com/d2learn/xlings/releases/download/v0.4.30/xlings-0.4.30-linux-x86_64.tar.gz | tar -xzf - -C /tmp
+          /tmp/xlings-0.4.30-linux-x86_64/subos/default/bin/xlings self install
+          export PATH="$HOME/.xlings/subos/default/bin:$PATH"
+          xlings install mcpp -y
+          echo "$HOME/.xlings/subos/default/bin" >> "$GITHUB_PATH"
+          mcpp --version
+
+      - name: "GCC: mcpp new → run"
+        run: |
+          cd "$(mktemp -d)"
+          mcpp new hello_gcc
+          cd hello_gcc
+          mcpp run
+
+      - name: "GCC: build mcpp"
+        run: |
+          mcpp clean
+          mcpp build
+
+      - name: "musl-gcc: mcpp new → run"
+        run: |
+          mcpp toolchain install gcc 15.1.0-musl
+          mcpp toolchain default gcc@15.1.0-musl
+          cd "$(mktemp -d)"
+          mcpp new hello_musl
+          cd hello_musl
+          mcpp run
+
+      - name: "musl-gcc: build mcpp"
+        run: |
+          mcpp toolchain default gcc@15.1.0-musl
+          mcpp clean
+          mcpp build
+
+      - name: "LLVM: mcpp new → run"
+        run: |
+          mcpp self config --mirror GLOBAL
+          mcpp toolchain install llvm 20.1.7
+          mcpp toolchain default llvm@20.1.7
+          cd "$(mktemp -d)"
+          mcpp new hello_llvm
+          cd hello_llvm
+          mcpp run
+
+      - name: "LLVM: build mcpp"
+        run: |
+          mcpp toolchain default llvm@20.1.7
+          mcpp clean
+          mcpp build
+
+  # ──────────────────────────────────────────────────────────────────
+  # macOS: llvm@20.1.7
+  # ──────────────────────────────────────────────────────────────────
+  macos-fresh:
+    name: macOS fresh install
+    runs-on: macos-15
+    timeout-minutes: 30
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install xlings + mcpp
+        env:
+          XLINGS_NON_INTERACTIVE: '1'
+        run: |
+          curl -fsSL https://github.com/d2learn/xlings/releases/download/v0.4.30/xlings-0.4.30-macosx-arm64.tar.gz | tar -xzf - -C /tmp
+          /tmp/xlings-0.4.30-macosx-arm64/subos/default/bin/xlings self install
+          export PATH="$HOME/.xlings/subos/default/bin:$PATH"
+          xlings install mcpp -y
+          echo "$HOME/.xlings/subos/default/bin" >> "$GITHUB_PATH"
+          mcpp --version
+
+      - name: "LLVM: mcpp new → run"
+        run: |
+          cd "$(mktemp -d)"
+          mcpp new hello_mac
+          cd hello_mac
+          mcpp run
+
+      - name: "LLVM: build mcpp"
+        run: |
+          mcpp clean
+          mcpp build
+
+  # ──────────────────────────────────────────────────────────────────
+  # Windows: llvm@20.1.7 + MSVC STL
+  # ──────────────────────────────────────────────────────────────────
+  windows-fresh:
+    name: Windows fresh install
+    runs-on: windows-latest
+    timeout-minutes: 30
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install xlings + mcpp
+        shell: pwsh
+        env:
+          XLINGS_NON_INTERACTIVE: '1'
+        run: |
+          Invoke-WebRequest -Uri "https://github.com/d2learn/xlings/releases/download/v0.4.30/xlings-0.4.30-windows-x86_64.zip" -OutFile "$env:TEMP\xlings.zip"
+          Expand-Archive -Path "$env:TEMP\xlings.zip" -DestinationPath "$env:TEMP\xlings-extract" -Force
+          & "$env:TEMP\xlings-extract\xlings-0.4.30-windows-x86_64\subos\default\bin\xlings.exe" self install
+          $xlingsbin = "$env:USERPROFILE\.xlings\subos\default\bin"
+          $env:PATH = "$xlingsbin;$env:PATH"
+          xlings install mcpp -y
+          $xlingsbin | Out-File -Append -FilePath $env:GITHUB_PATH -Encoding utf8
+          mcpp --version
+
+      - name: "LLVM: mcpp new → run"
+        shell: pwsh
+        run: |
+          $tmp = New-TemporaryFile | ForEach-Object { Remove-Item $_; New-Item -ItemType Directory -Path $_ }
+          Set-Location $tmp
+          mcpp new hello_win
+          Set-Location hello_win
+          mcpp run
+
+      - name: "LLVM: build mcpp"
+        shell: pwsh
+        run: |
+          mcpp clean
+          mcpp build

.github/workflows/ci-macos.yml

@@ -306,14 +306,14 @@ jobs:
           "$MCPP" toolchain default llvm@20.1.7
           bash tests/e2e/run_all.sh
 
-      - name: Self-host smoke (freshly-built mcpp builds itself again)
+      - name: "Toolchain: LLVM — build mcpp (self-host)"
         run: |
           MCPP=$(find target -path "*/bin/mcpp" | head -1)
           MCPP=$(cd "$(dirname "$MCPP")" && pwd)/$(basename "$MCPP")
           test -x "$MCPP"
-          export PATH="$(dirname "$MCPP"):$PATH"
+          cp "$MCPP" /tmp/mcpp-fresh
+          MCPP=/tmp/mcpp-fresh
+          "$MCPP" toolchain default llvm@20.1.7
+          "$MCPP" clean
           "$MCPP" build
           "$MCPP" --version
-          echo ":: Self-host smoke PASS"
-
-      # Fresh user experience test moved to ci-fresh-install.yml (PR #63)

.github/workflows/ci-windows.yml

@@ -96,19 +96,29 @@ jobs:
           export MCPP="$MCPP_SELF"
           export MCPP_VENDORED_XLINGS="$XLINGS_BIN"
           export MCPP_E2E_TOOLCHAIN_MIRROR=GLOBAL
-          "$MCPP_SELF" self config --mirror GLOBAL 2>/dev/null || true
-          "$MCPP_SELF" toolchain default llvm@20.1.7 2>/dev/null || true
+          "$MCPP_SELF" self config --mirror GLOBAL
+          "$MCPP_SELF" toolchain default llvm@20.1.7
           bash tests/e2e/run_all.sh
 
-      - name: Self-host smoke (freshly-built mcpp builds itself again)
+      - name: "Toolchain: LLVM — mcpp new → run"
         shell: bash
         run: |
           export MCPP_VENDORED_XLINGS="$XLINGS_BIN"
-          "$MCPP_SELF" build
-          "$MCPP_SELF" --version
-          echo ":: Self-host smoke PASS"
+          TMP=$(mktemp -d)
+          cd "$TMP"
+          "$MCPP_SELF" new hello_win
+          cd hello_win
+          "$MCPP_SELF" run
 
-      # Fresh user experience test moved to ci-fresh-install.yml (PR #63)
+      - name: "Toolchain: LLVM — build mcpp (self-host)"
+        shell: bash
+        run: |
+          export MCPP_VENDORED_XLINGS="$XLINGS_BIN"
+          cp "$MCPP_SELF" /tmp/mcpp-fresh.exe
+          MCPP=/tmp/mcpp-fresh.exe
+          "$MCPP" toolchain default llvm@20.1.7
+          "$MCPP" clean --bmi-cache
+          "$MCPP" build 2>&1 | tee build.log; grep -q "Resolved llvm@20.1.7" build.log
 
       - name: Package Windows release zip
         id: package
@@ -118,9 +128,12 @@ jobs:
           WRAPPER="mcpp-${VERSION}-windows-x86_64"
           ZIPNAME="${WRAPPER}.zip"
 
+          MCPP_BIN=$(find target -name "mcpp.exe" -path "*/bin/*" | head -1)
+          test -n "$MCPP_BIN" || { echo "FAIL: no mcpp.exe in target/"; exit 1; }
+
           STAGING=$(mktemp -d)
           mkdir -p "$STAGING/$WRAPPER/bin" "$STAGING/$WRAPPER/registry/bin"
-          cp "$MCPP_SELF" "$STAGING/$WRAPPER/bin/mcpp.exe"
+          cp "$MCPP_BIN" "$STAGING/$WRAPPER/bin/mcpp.exe"
           printf '@echo off\r\n"%%~dp0bin\\mcpp.exe" %%*\r\n' > "$STAGING/$WRAPPER/mcpp.bat"
           cp README.md "$STAGING/$WRAPPER/" 2>/dev/null || true
           cp LICENSE "$STAGING/$WRAPPER/" 2>/dev/null || true

.github/workflows/ci.yml

@@ -128,39 +128,29 @@ jobs:
           "$MCPP" toolchain default gcc@16.1.0
           bash tests/e2e/run_all.sh
 
-      - name: Self-host smoke (freshly-built mcpp builds itself again)
+      - name: Save freshly-built mcpp for toolchain tests
         run: |
           MCPP=$(realpath "$(find target -type f -name mcpp -printf '%T@ %p\n' | sort -rn | head -1 | cut -d' ' -f2)")
-          "$MCPP" build
-          "$MCPP" test
+          cp "$MCPP" /tmp/mcpp-fresh
+          echo "MCPP=/tmp/mcpp-fresh" >> "$GITHUB_ENV"
 
-      - name: "Toolchain: GCC — mcpp new → build → run"
+      - name: "Toolchain: GCC — build mcpp + test"
         run: |
-          MCPP=$(realpath "$(find target -type f -name mcpp -printf '%T@ %p\n' | sort -rn | head -1 | cut -d' ' -f2)")
-          "$MCPP" toolchain default gcc@16.1.0
-          TMP=$(mktemp -d)
-          cd "$TMP"
-          "$MCPP" new hello_gcc
-          cd hello_gcc
-          "$MCPP" run
+          "$MCPP" clean
+          "$MCPP" build 2>&1 | tee build.log; grep -q "Resolved gcc@16.1.0" build.log
+          "$MCPP" test
 
-      - name: "Toolchain: musl-gcc — mcpp new → build → run"
+      - name: "Toolchain: musl-gcc — build mcpp (--target)"
         run: |
-          MCPP=$(realpath "$(find target -type f -name mcpp -printf '%T@ %p\n' | sort -rn | head -1 | cut -d' ' -f2)")
-          "$MCPP" toolchain default gcc@15.1.0-musl
-          TMP=$(mktemp -d)
-          cd "$TMP"
-          "$MCPP" new hello_musl
-          cd hello_musl
-          "$MCPP" run
+          "$MCPP" clean
+          "$MCPP" build --target x86_64-linux-musl 2>&1 | tee build.log; grep -q "Resolved gcc@15.1.0-musl" build.log
 
-      - name: "Toolchain: LLVM — install + mcpp new → build → run"
+      - name: "Toolchain: LLVM — build mcpp"
         run: |
-          MCPP=$(realpath "$(find target -type f -name mcpp -printf '%T@ %p\n' | sort -rn | head -1 | cut -d' ' -f2)")
           "$MCPP" toolchain install llvm 20.1.7
-          "$MCPP" toolchain default llvm@20.1.7
-          TMP=$(mktemp -d)
-          cd "$TMP"
-          "$MCPP" new hello_llvm
-          cd hello_llvm
-          "$MCPP" run
+          # Override project toolchain to use LLVM for this build
+          sed -i 's/^default = "gcc@16.1.0"/default = "llvm@20.1.7"/' mcpp.toml
+          "$MCPP" clean
+          "$MCPP" build 2>&1 | tee build.log; grep -q "Resolved llvm@20.1.7" build.log
+          # Restore
+          sed -i 's/^default = "llvm@20.1.7"/default = "gcc@16.1.0"/' mcpp.toml