[dpdk-dev] [PATCH v2] doc: fix doc build when sphinx reports version to stderr

[Bruce Richardson <bruce.richardson@intel.com>]

When sphinx-build reports its version information to stderr rather
than stdout, the wrapper script misses it, and then fails to run.
We can fix this by redirecting stderr to stdout for the version
query call.

Fixes: f5ab2074cfba ("doc: rebuild with meson whenever a file changes")

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
---
V2: no changes to this patch, dropped patch 2 from series.
---
 buildtools/call-sphinx-build.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/buildtools/call-sphinx-build.py b/buildtools/call-sphinx-build.py
index b9a3994e1..85c9e0156 100755
--- a/buildtools/call-sphinx-build.py
+++ b/buildtools/call-sphinx-build.py
@@ -6,13 +6,14 @@
 import sys
 import os
 from os.path import join
-from subprocess import run, PIPE
+from subprocess import run, PIPE, STDOUT
 from distutils.version import StrictVersion
 
 (sphinx, src, dst) = sys.argv[1:]  # assign parameters to variables
 
 # for sphinx version >= 1.7 add parallelism using "-j auto"
-ver = run([sphinx, '--version'], stdout=PIPE).stdout.decode().split()[-1]
+ver = run([sphinx, '--version'], stdout=PIPE,
+          stderr=STDOUT).stdout.decode().split()[-1]
 sphinx_cmd = [sphinx]
 if StrictVersion(ver) >= StrictVersion('1.7'):
     sphinx_cmd += ['-j', 'auto']
-- 
2.25.1