build: disable pylint check by default

Disable the pylint check in src/bindings/python/flux by default.
Introduce a new `--enable-pylint` option to configure to enable the
check at configure time.

Fixes flux-framework#1250

configure.ac

@@ -180,6 +180,17 @@ if test "$enable_python" = "yes"; then
 fi
 AM_CONDITIONAL([HAVE_PYTHON], [test "$enable_python" = yes])
 
+AC_ARG_ENABLE([pylint],
+  [AS_HELP_STRING([--enable-pylint],
+    [Enable pylint checks of python bindings])],,
+  [enable_pylint="yes"]
+)
+AS_IF([test "x$enable_pylint" = "xyes"], [
+  AC_CHECK_PROG(PYLINT,[pylint],[pylint])
+  AS_IF([test "x$PYLINT" != "xpylint"], [AC_MSG_ERROR([No pylint found in PATH])])
+])
+AM_CONDITIONAL([ENABLE_PYLINT], [test "x$PYLINT" = "xpylint"])
+
 AX_PROG_LUA([5.1],[5.3])
 AX_LUA_HEADERS
 AX_LUA_LIBS

src/bindings/python/flux/Makefile.am

@@ -98,10 +98,12 @@ lib-copy: ${fluxpy_PYTHON} ${fluxpy_LTLIBRARIES}
 	done
 	[ "$(top_srcdir)" != "$(top_builddir)" ] && cp $(top_srcdir)/src/bindings/python/flux/*.py ./ || true
 
+if ENABLE_PYLINT
 #TODO: there must be a better way to do this
 # scan flux bindings with pylint, currently fails on any exit but 0
 check-local: lib-copy
 	if [ -x "$$( which pylint )" ] ; then  pylint --rcfile=$(top_srcdir)/src/bindings/python/.pylintrc ../flux ; fi
+endif
 
 all-local: lib-copy