Re: [PATCH v2 01/30] configure: Allow user to specify sphinx-build binary

[Markus Armbruster]

Does not work out of the box on my Fedora 30 build host, where
sphinx-build gives me sphinx-build-2.  I have to specify
--sphinx-build=/usr/bin/sphinx-build-3 to unbreak it.  Which of course
breaks things when I try to build anything before this commit

The appended patch makes it work out of the box.  Please consider
squashing it in.

diff --git a/configure b/configure
index 14172909f0..a9d175c400 100755
--- a/configure
+++ b/configure
@@ -584,7 +584,6 @@ query_pkg_config() {
 }
 pkg_config=query_pkg_config
 sdl2_config="${SDL2_CONFIG-${cross_prefix}sdl2-config}"
-sphinx_build=sphinx-build
 
 # If the user hasn't specified ARFLAGS, default to 'rv', just as make does.
 ARFLAGS="${ARFLAGS-rv}"
@@ -903,6 +902,7 @@ fi
 
 : ${make=${MAKE-make}}
 : ${install=${INSTALL-install}}
+
 # We prefer python 3.x. A bare 'python' is traditionally
 # python 2.x, but some distros have it as python 3.x, so
 # we check that too
@@ -915,6 +915,19 @@ do
         break
     fi
 done
+
+set -x
+sphinx_build=
+for binary in sphinx-build-3 sphinx-build
+do
+    if has "$binary"
+    then
+        sphinx_build=$(command -v "$binary")
+        break
+    fi
+done
+set +x
+
 : ${smbd=${SMBD-/usr/sbin/smbd}}
 
 # Default objcc to clang if available, otherwise use CC
@@ -4803,7 +4816,7 @@ has_sphinx_build() {
     # sphinx-build doesn't exist at all or if it is too old.
     mkdir -p "$TMPDIR1/sphinx"
     touch "$TMPDIR1/sphinx/index.rst"
-    $sphinx_build -c "$source_path/docs" -b html "$TMPDIR1/sphinx" 
"$TMPDIR1/sphinx/out" >/dev/null 2>&1
+    "$sphinx_build" -c "$source_path/docs" -b html "$TMPDIR1/sphinx" 
"$TMPDIR1/sphinx/out" >/dev/null 2>&1
 }
 
 # Check if tools are available to build documentation.