Merge pull request #3 from lsst/tickets/DM-2303

Force eups operations during install to run in serial.

python/lsst/sconsUtils/installation.py

@@ -323,15 +323,16 @@ def InstallEups(env, dest, files=[], presetup=""):
         except ImportError:
             state.log.warn("Unable to import eups; not locking")
 
+        eupsTargets = []
+
         for i in build_obj:
             env.AlwaysBuild(i)
 
             cmd = "eups expandbuild -i --version %s " % env['version']
             if env.has_key('baseversion'):
                 cmd += " --repoversion %s " % env['baseversion']
             cmd += str(i)
-
-            env.AddPostAction(build_obj, env.Action("%s" %(cmd), cmd))
+            eupsTargets.extend(env.AddPostAction(build_obj, env.Action("%s" %(cmd), cmd)))
 
         for i in table_obj:
             env.AlwaysBuild(i)
@@ -342,9 +343,16 @@ def InstallEups(env, dest, files=[], presetup=""):
             cmd += str(i)
 
             act = env.Command("table", "", env.Action("%s" %(cmd), cmd))
+            eupsTargets.extend(act)
             acts += act
             env.Depends(act, i)
 
+        # By declaring that all the Eups operations create a file called "eups" as a side-effect,
+        # even though they don't, SCons knows it can't run them in parallel (it thinks of the
+        # side-effect file as something like a log, and knows you shouldn't be appending to it
+        # in parallel).  When Eups locking is working, we may be able to remove this.
+        env.SideEffect("eups", eupsTargets)
+
     return acts
 
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