fix: 3.x-dev can install a 3.y version

.github/workflows/test-python.yml

@@ -120,3 +120,30 @@ jobs:
     - name: Run simple code
       run: python -c 'import math; print(math.factorial(5))'
 
+  setup-dev-version:
+    name: Setup 3.9-dev ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [macos-latest, windows-latest, ubuntu-latest]
+    steps:
+    - name: Checkout
+      uses: actions/checkout@v3
+
+    - name: setup-python 3.9-dev
+      id: setup-python
+      uses: ./
+      with:
+        python-version: '3.9-dev'
+
+    - name: Check python-path
+      run: ./__tests__/check-python-path.sh '${{ steps.setup-python.outputs.python-path }}'
+      shell: bash
+
+    - name: Validate version
+      run: ${{ startsWith(steps.setup-python.outputs.python-version, '3.9.') }}
+      shell: bash
+
+    - name: Run simple code
+      run: python -c 'import math; print(math.factorial(5))'

dist/setup/index.js

@@ -64183,15 +64183,10 @@ function useCpythonVersion(version, architecture) {
     });
 }
 exports.useCpythonVersion = useCpythonVersion;
-/** Convert versions like `3.8-dev` to a version like `>= 3.8.0-a0`. */
+/** Convert versions like `3.8-dev` to a version like `~3.8.0-0`. */
 function desugarDevVersion(versionSpec) {
-    if (versionSpec.endsWith('-dev')) {
-        const versionRoot = versionSpec.slice(0, -'-dev'.length);
-        return `>= ${versionRoot}.0-a0`;
-    }
-    else {
-        return versionSpec;
-    }
+    const devVersion = /^(\d+)\.(\d+)-dev$/;
+    return versionSpec.replace(devVersion, '~$1.$2.0-0');
 }
 /** Extracts python version from install path from hosted tool cache as described in README.md */
 function versionFromPath(installDir) {

src/find-python.ts

@@ -117,14 +117,10 @@ export async function useCpythonVersion(
   return {impl: 'CPython', version: installed};
 }
 
-/** Convert versions like `3.8-dev` to a version like `>= 3.8.0-a0`. */
+/** Convert versions like `3.8-dev` to a version like `~3.8.0-0`. */
 function desugarDevVersion(versionSpec: string) {
-  if (versionSpec.endsWith('-dev')) {
-    const versionRoot = versionSpec.slice(0, -'-dev'.length);
-    return `>= ${versionRoot}.0-a0`;
-  } else {
-    return versionSpec;
-  }
+  const devVersion = /^(\d+)\.(\d+)-dev$/;
+  return versionSpec.replace(devVersion, '~$1.$2.0-0');
 }
 
 /** Extracts python version from install path from hosted tool cache as described in README.md */