Use pipefail when available.
This change makes test with RUN lines like
RUN: opt ... | FileCheck
fail if opt fails, even if it prints what FileCheck wants. Enabling this
found some interesting cases of broken tests that were not being noticed
because opt (or some other tool) was crashing late.
Pipefail is used when the shell supports it or when using the internal
python based tester.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187261 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/CommandGuide/lit.rst b/docs/CommandGuide/lit.rst
index 2f6d9a1..a4681fb 100644
--- a/docs/CommandGuide/lit.rst
+++ b/docs/CommandGuide/lit.rst
@@ -316,6 +316,10 @@
*on_clone* function will generally modify), and (3) the test path to the new
directory being scanned.
+ **pipefail** Normally a test using a shell pipe fails if any of the commands
+ on the pipe fail. If this is not desired, setting this variable to false
+ makes the test fail only if the last command in the pipe fails.
+
TEST DISCOVERY
~~~~~~~~~~~~~~