DOC: Making the build fail if the doc build fails (#24292)

Author: datapythonista

.travis.yml

@@ -112,7 +112,7 @@ before_script:
 script:
   - echo "script start"
   - source activate pandas-dev
-  - ci/run_build_docs.sh
+  - ci/build_docs.sh
   - ci/run_tests.sh
 
 after_script:

ci/build_docs.sh

@@ -1,5 +1,7 @@
 #!/bin/bash
 
+set -e
+
 if [ "${TRAVIS_OS_NAME}" != "linux" ]; then
    echo "not doing build_docs on non-linux"
    exit 0

ci/run_build_docs.sh

@@ -214,7 +214,10 @@ def _run_os(*args):
         # TODO check_call should be more safe, but it fails with
         # exclude patterns, needs investigation
         # subprocess.check_call(args, stderr=subprocess.STDOUT)
-        os.system(' '.join(args))
+        exit_status = os.system(' '.join(args))
+        if exit_status:
+            msg = 'Command "{}" finished with exit code {}'
+            raise RuntimeError(msg.format(' '.join(args), exit_status))
 
     def _sphinx_build(self, kind):
         """Call sphinx to build documentation.