--- ghc-8.2.2/configure.ac~	2017-11-21 05:22:42.000000000 +0900

+++ ghc-8.2.2/configure.ac	2018-05-28 12:37:35.296728423 +0900

@@ -745,7 +745,7 @@

 AC_CACHE_CHECK([for version of sphinx-build], fp_cv_sphinx_version,

 changequote(, )dnl

 [if test -n "$SPHINXBUILD"; then

-  fp_cv_sphinx_version=`"$SPHINXBUILD" --version 2>&1 | sed 's/Sphinx\( (sphinx-build)\)\? v\?\([0-9]\.[0-9]\.[0-9]\)/\2/' | head -n1`;

+  fp_cv_sphinx_version=`"$SPHINXBUILD" --version 2>&1 | sed 's/.* v\?\([0-9]\.[0-9]\.[0-9]\)/\1/' | head -n1`;

 fi;

 changequote([, ])dnl

 ])