diff -Nru whalebuilder-0.5/build.sh.erb whalebuilder-0.5.1/build.sh.erb
--- whalebuilder-0.5/build.sh.erb	2017-08-01 22:32:09.000000000 +0000
+++ whalebuilder-0.5.1/build.sh.erb	2017-08-11 19:05:56.000000000 +0000
@@ -1,6 +1,6 @@
-#!/bin/sh
+#!/bin/bash
 
-set -e
+set -eo pipefail
 
 cd /build
 dpkg-source -x ~/source/<%= @dscfilename %>
diff -Nru whalebuilder-0.5/debian/changelog whalebuilder-0.5.1/debian/changelog
--- whalebuilder-0.5/debian/changelog	2017-08-10 14:58:36.000000000 +0000
+++ whalebuilder-0.5.1/debian/changelog	2017-08-11 19:08:21.000000000 +0000
@@ -1,3 +1,9 @@
+whalebuilder (0.5.1) unstable; urgency=medium
+
+  * use pipefail to make sure that build failures are caught
+
+ -- Hubert Chathi <uhoreg@debian.org>  Fri, 11 Aug 2017 15:08:21 -0400
+
 whalebuilder (0.5) unstable; urgency=medium
 
   * allow installing extra .debs when building dependency image
diff -Nru whalebuilder-0.5/whalebuilder whalebuilder-0.5.1/whalebuilder
--- whalebuilder-0.5/whalebuilder	2017-08-06 21:54:52.000000000 +0000
+++ whalebuilder-0.5.1/whalebuilder	2017-08-11 19:06:40.000000000 +0000
@@ -464,7 +464,7 @@
     # build the package
     docker "run", "--user=whalebuilder", "--name=#{containername}",
            "-v", "#{dir}/source:/home/whalebuilder/source:ro",
-           "--net=none", name, "/bin/sh", "/home/whalebuilder/source/build.sh" or
+           "--net=none", name, "/bin/bash", "/home/whalebuilder/source/build.sh" or
       abort "[whalebuilder] E: docker run failed with error #{$?}"
     r, w = IO.pipe
     pid = spawn(*(make_docker_command "cp", "#{containername}:/build/.", "-"), :out => w)