Add pants_from_sources support. (#77)

Closes #30

Author: jsirois

.github/workflows/ci.yml

@@ -28,6 +28,9 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-22.04, macos-11, macOS-11-ARM64, windows-2022]
+    env:
+      PY: python3.9
+      SCIE_PANTS_DEV_CACHE: .scie_pants_dev_cache
     steps:
       - uses: actions/checkout@v3
       - name: Check Formatting
@@ -38,6 +41,18 @@ jobs:
         run: cargo clippy --all
       - name: Unit Tests
         run: cargo test --all
+      - name: Setup Python 3.9
+        if: ${{ matrix.os == 'ubuntu-22.04' || matrix.os == 'macos-11' }}
+        uses: actions/setup-python@v4
+        with:
+          # N.B.: We need Python 3.9 for running Pants goals against our tools.pex Python tools
+          # codebase as well as running Pants from sources in ITs.
+          python-version: "3.9"
+      - name: Cache Build and IT Artifacts
+        uses: actions/cache@v3
+        with:
+          path: ${{ env.SCIE_PANTS_DEV_CACHE }}
+          key: ${{ runner.os }}-${{ runner.arch }}-scie-pants-v0
       - name: Build, Package & Integration Tests
         if: ${{ matrix.os == 'macOS-11-ARM64' }}
         run: |
@@ -58,13 +73,6 @@ jobs:
         run: |
           PANTS_BOOTSTRAP_GITHUB_API_BEARER_TOKEN=${{ secrets.GITHUB_TOKEN }} \
             cargo run -p package -- test
-      - name: Setup Python 3.9
-        if: ${{ matrix.os == 'ubuntu-22.04' }}
-        uses: actions/setup-python@v4
-        with:
-          # N.B.: We need Python 3.9 for running Pants goals against our tools.pex Python tools
-          # codebase.
-          python-version: "3.9"
       - name: Build, Package & Integration Tests
         if: ${{ matrix.os == 'ubuntu-22.04' }}
         run: |
@@ -85,4 +93,3 @@ jobs:
             cargo run -p package -- test \
               --tools-pex dist/tools.pex --scie-pants dist/scie-pants-linux-x86_64 \
               --tools-pex-mismatch-warn
-

BUILD_ROOT

@@ -1,5 +1,23 @@
 # Release Notes
 
+## 0.3.0
+
+This release adds support for running Pants from a local Pants clone. This is useful for testing out
+unreleased Pants changes.
+
+This feature used to be provided by a bespoke `pants_from_sources` script copied around to various
+repositories; an example of which is [here](
+https://github.com/pantsbuild/example-python/blob/1b38d08821865e3756024950bc000bdbd0161b95/pants_from_sources).
+
+There are two ways to activate this mode:
+1. Execute `pants` with the `PANTS_SOURCE` environment variable set as the path to the Pants repo
+   whose Pants code you'd like to run against your repo.
+2. Copy, hardlink or symlink your `pants` binary to `pants_from_sources` and execute that.
+
+The first activation method is new. The second mode follows the bespoke `./pants_from_sources`
+conventions and assumes `PANTS_SOURCE=../pants`. You can override that by setting the`PANTS_SOURCE`
+env var as in the first activation method.
+
 ## 0.2.2
 
 This release fixes the scie-pants scie to not expose the interpreter used to run a Pants

CHANGES.md

@@ -6,7 +6,7 @@ members = [
 [package]
 name = "scie-pants"
 description = "Protects your Pants from the elements."
-version = "0.2.2"
+version = "0.3.0"
 edition = "2021"
 authors = [
     "John Sirois <[email protected]>",

Cargo.lock

@@ -63,6 +63,13 @@ provides the following:
   If you run `scie-pants` in a directory where Pants is not already set up, it will prompt you, and
   you can let it set up the latest Pants stable version for your project.
 
++ Built-in [`pants_from_sources`](
+  https://github.com/pantsbuild/example-python/blob/1b38d08821865e3756024950bc000bdbd0161b95/pants_from_sources)
+  support. You can either execute `scie-pants` with `PANTS_SOURCE` set to the path of a local clone
+  of the [Pants](https://github.com/pantsbuild/pants) repo or else copy, link or symlink your
+  `scie-pants` executable to `pants_from_sources` and execute that. In this case `PANTS_SOURCE` will
+  default to `../pants` just as was the case in the bespoke `./pants_from_sources` scripts.
+
 + Partial support for firewalls:
 
   Currently, you can only re-direct the URLs scie-pants uses to fetch [Python Build Standalone](