diff --git a/ognibuild/__init__.py b/ognibuild/__init__.py
index 366f1f8..a74a55b 100644
--- a/ognibuild/__init__.py
+++ b/ognibuild/__init__.py
@@ -31,6 +31,8 @@ class DetailedFailure(Exception):
 
 
 class UnidentifiedError(Exception):
+    """An unidentified error."""
+
     def __init__(self, retcode, argv, lines, secondary=None):
         self.retcode = retcode
         self.argv = argv
diff --git a/ognibuild/debian/__init__.py b/ognibuild/debian/__init__.py
index 8879a4c..23a56a1 100644
--- a/ognibuild/debian/__init__.py
+++ b/ognibuild/debian/__init__.py
@@ -15,14 +15,14 @@
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 
+import os
 from debian.deb822 import Deb822
 
 from ..session import Session
 
 
-# TODO(jelmer): move this to debian/
-def satisfy_build_deps(session: Session, tree):
-    source = Deb822(tree.get_file("debian/control"))
+def satisfy_build_deps(session: Session, tree, debian_path):
+    source = Deb822(tree.get_file(os.path.join(debian_path, "control")))
     deps = []
     for name in ["Build-Depends", "Build-Depends-Indep", "Build-Depends-Arch"]:
         try:
diff --git a/ognibuild/dist.py b/ognibuild/dist.py
index 5277a52..a9bc20f 100644
--- a/ognibuild/dist.py
+++ b/ognibuild/dist.py
@@ -141,7 +141,6 @@ def create_dist(
     session: Session,
     tree: Tree,
     target_dir: str,
-    packaging_tree: Optional[Tree] = None,
     include_controldir: bool = True,
     subdir: Optional[str] = None,
     cleanup: bool = False
@@ -151,11 +150,6 @@ def create_dist(
 
     if subdir is None:
         subdir = "package"
-    if packaging_tree is not None:
-        from .debian import satisfy_build_deps
-
-        satisfy_build_deps(session, packaging_tree)
-
     try:
         export_directory, reldir = session.setup_from_vcs(
             tree, include_controldir=include_controldir, subdir=subdir)
@@ -189,14 +183,18 @@ def create_dist_schroot(
     target_dir: str,
     chroot: str,
     packaging_tree: Optional[Tree] = None,
+    packaging_subpath: Optional[str] = None,
     include_controldir: bool = True,
     subdir: Optional[str] = None,
     cleanup: bool = False
 ) -> Optional[str]:
     with SchrootSession(chroot) as session:
+        if packaging_tree is not None:
+            from .debian import satisfy_build_deps
+
+            satisfy_build_deps(session, packaging_tree, packaging_subpath)
         return create_dist(
             session, tree, target_dir,
-            packaging_tree=packaging_tree,
             include_controldir=include_controldir,
             subdir=subdir,
             cleanup=cleanup)