diff --git a/docker/utils/pyutils.sh b/docker/utils/pyutils.sh
--- a/docker/utils/pyutils.sh
+++ b/docker/utils/pyutils.sh
@@ -1,16 +1,25 @@
 #!/bin/bash
 
+
 setup_pip () {
   echo Using pip from $(which pip)
 
   if [[ -d /src ]] ; then
     tmpdir=`mktemp -d`
-    # Source directories might not be writeable, but building them writes
-    # in-tree; so we're copying them to a location guaranteed to be writeable.
-    rsync -a /src/ $tmpdir/ --exclude "*/__pycache__/" --exclude "*/.tox/" --exclude "*/.hypothesis/"
-    for srcrepo in $tmpdir/swh-* ; do
-      pip install $srcrepo
+    pushd /src
+    for srcrepo in swh-* ; do
+      if [ -w $srcrepo ]
+      then
+        # Install package in editable mode if source directory is writable
+        pip install -e $srcrepo
+      else
+        # Source directories might not be writeable, but building them writes
+        # in-tree; so we're copying them to a location guaranteed to be writeable.
+        rsync -a --chmod=+w $srcrepo $tmpdir/ --exclude "*/__pycache__/" --exclude "*/.tox/" --exclude "*/.hypothesis/"
+        pip install $tmpdir/$srcrepo
+      fi
     done
+    popd
     rm -rf $tmpdir
   fi