From eb96c972d2178bf49bcbe6c10c088c45bd093180 Mon Sep 17 00:00:00 2001
From: "Erik M. Bray" <erik.bray@lri.fr>
Date: Thu, 19 Jul 2018 07:28:29 +0000
Subject: [PATCH] rather than try to make _clean-broken-gcc explicitly a
 prerequisite of spkg targets just ensure it is always run/checked in the
 build/make/install script

it also needs to run as a prerequisite of base-toolchain
---
 build/make/deps             | 2 +-
 build/make/install          | 5 +++++
 build/pkgs/gcc/dependencies | 2 +-
 m4/sage_spkg_collect.m4     | 4 ----
 4 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/build/make/deps b/build/make/deps
index fb9a6e4a031..1968f5518b1 100644
--- a/build/make/deps
+++ b/build/make/deps
@@ -47,7 +47,7 @@ all-build: toolchain-deps
 # During the toolchain build, we export SAGE_BUILD_TOOLCHAIN=yes
 # such that packages can do different things when they are built
 # as prerequisite of GCC.
-base-toolchain: base
+base-toolchain: _clean-broken-gcc base
 	env SAGE_BUILD_TOOLCHAIN=yes $(MAKE) toolchain
 
 # All targets except for the base packages
diff --git a/build/make/install b/build/make/install
index 5873cf2dc3f..f0a1fb82508 100755
--- a/build/make/install
+++ b/build/make/install
@@ -44,6 +44,11 @@ if [ -z "$MAKE" ]; then
     export MAKE=make
 fi
 
+# Make the special target _clean-broken-gcc before trying to build any other
+# packages.  This is necessary if configure detected a broken GCC installed
+# in Sage; Trac #25011
+$MAKE _clean-broken-gcc
+
 # If "make" doesn't understand the -q option (although we require
 # GNU make, which supports it), it should exit with a non-zero status
 # which is not a problem.
diff --git a/build/pkgs/gcc/dependencies b/build/pkgs/gcc/dependencies
index fbd8586f0e4..9af2c9534bb 100644
--- a/build/pkgs/gcc/dependencies
+++ b/build/pkgs/gcc/dependencies
@@ -1,4 +1,4 @@
-_clean-broken-gcc | $(MP_LIBRARY) mpfr mpc zlib xz
+| $(MP_LIBRARY) mpfr mpc zlib xz
 
 ------------------------------------------------------------------------
 NOTE: all dependencies of GCC must be order-only dependencies
diff --git a/m4/sage_spkg_collect.m4 b/m4/sage_spkg_collect.m4
index 11123071d1b..beb64d2ffd9 100644
--- a/m4/sage_spkg_collect.m4
+++ b/m4/sage_spkg_collect.m4
@@ -58,10 +58,6 @@ AC_DEFUN_ONCE([SAGE_SPKG_COLLECT], [
 # See https://trac.sagemath.org/ticket/24703
 if test x$SAGE_INSTALL_GCC = xexists; then
     SAGE_GCC_DEP='$(SAGE_LOCAL)/bin/gcc'
-elif test x$SAGE_INSTALL_GCC = xyes; then
-    # GCC should be installed *or* there as in existing installation that
-    # is broken and should be removed.
-    SAGE_GCC_DEP='_clean-broken-gcc'
 else
     SAGE_GCC_DEP=''
 fi