morphlib: add buildenvironment and tests

BuildEnvironment should contain all the information about whatever
settings affect the build. A subset of these will affect the cache
key, but CacheKeyComputer filters them itself.

BuildEnvironment has consumed the purpose of Morph.clean_env() because
the build environment is a good place to store this information.

The environment variables are decided based on the current settings.
The current environment can be accessed by the env attribute.

The tests are a little invasive because it reads environment variables
and most of the work is done in the constructor, but they should test
everything useful.

1 files changed, 1 insertions, 0 deletions

diff --git a/morphlib/__init__.py b/morphlib/__init__.py
index 26727929..adb0fa1e 100644
--- a/morphlib/__init__.py
+++ b/morphlib/__init__.py
@@ -23,6 +23,7 @@ import blobs
 import buildcontroller
 import builddependencygraph
 import buildgraph
+import buildenvironment
 import buildsystem
 import buildworker
 import builder