[dpdk-stable] [PATCH] doc: fix build on Windows with meson 0.58

[Dmitry Kozlyuk]

The `doc` target used `echo` as its command.
On Windows, `echo` is always a shell built-in, there is no binary.
Starting from meson 0.58, `run_target()` always searches for command
executable and no longer accepts `echo` as such on Windows.
Replace plain `echo` with a Python one-liner.

Fixes: d02a2dab2dfb ("doc: support building HTML guides with meson")
Cc: Bruce Richardson <bruce.richardson at intel.com>
Cc: Luca Boccassi <bluca at debian.org>
Cc: stable at dpdk.org

Reported-by: Rob Scheepens <rob.scheepens at nutanix.com>
Signed-off-by: Dmitry Kozlyuk <dmitry.kozliuk at gmail.com>
---
 doc/meson.build | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/doc/meson.build b/doc/meson.build
index 959606b965..abd7d70421 100644
--- a/doc/meson.build
+++ b/doc/meson.build
@@ -11,5 +11,6 @@ if doc_targets.length() == 0
 else
     message = 'Building docs:'
 endif
-run_target('doc', command: ['echo', message, doc_target_names],
+echo = [py3, '-c', 'import sys; print(*sys.argv[1:])']
+run_target('doc', command: [echo, message, doc_target_names],
     depends: doc_targets)
-- 
2.29.3