Show how to build from source in README.md
diff --git a/README.md b/README.md
index 0dfb884..a31f66c 100644
--- a/README.md
+++ b/README.md
@@ -9,18 +9,19 @@
environment for the target platform. You will need to have a working Docker
installation before proceeding.
-1. Fetch a source distribution, such as an
- [official one](https://aurora.apache.org/downloads/).
+1. Fetch a source distribution, such as an [official one](https://aurora.apache.org/downloads/).
+ Alternatively, you can also build from an arbitrary git commit by instead preparing sources
+from the Aurora source repository:
+
+ git archive --prefix=apache-aurora-$(cat .auroraversion)/ -o snapshot.tar.gz HEAD
2. Run the builder script, providing the distribution platform and the source
distribution archive you downloaded in (1). The example below will build
Aurora 0.9.0 debs for Ubuntu Trusty.
- ```
- ./build-artifact.sh builder/deb/ubuntu-trusty \
- ~/Downloads/apache-aurora-0.9.0.tar.gz \
- 0.9.0
- ```
+ ./build-artifact.sh builder/deb/ubuntu-trusty \
+ ../apache-aurora-0.9.0.tar.gz \
+ 0.9.0
When this completes, debs will be placed in `dist/builder/deb/ubuntu-trusty/`.
@@ -31,4 +32,4 @@
- a `Dockerfile` to provide the repeatable build environment
- a `build.sh` script that creates artifacts
-Please see the makeup of other builders for examples.
\ No newline at end of file
+Please see the makeup of other builders for examples.
