Trac #29631: spkg-configure.m4 for linbox

This ticket adds an `spkg-configure.m4` for linbox, in order to use it
from a system package if possible (see #27330).

Note for packagers: by default, linbox produces a buggy `linbox.pc`, and
`@LINBOXSAGE_LIBS@` must be removed from their `linbox.pc.in` (see
#27205).

No more problem after that.

URL: https://trac.sagemath.org/29631
Reported by: gh-thierry-FreeBSD
Ticket author(s): Thierry Thomas, Michael Orlitzky, Samuel Lelièvre
Reviewer(s): Dima Pasechnik

build/pkgs/fplll/distros/debian.txt

@@ -0,0 +1 @@
+libfplll-dev

build/pkgs/linbox/dependencies

@@ -1,4 +1,4 @@
-$(MP_LIBRARY) ntl givaro mpfr fplll iml flint fflas_ffpack
+$(MP_LIBRARY) ntl givaro mpfr iml flint fflas_ffpack
 
 ----------
 All lines of this file are ignored except the first.

build/pkgs/linbox/distros/fedora.txt

@@ -0,0 +1 @@
+linbox

build/pkgs/linbox/distros/gentoo.txt

@@ -0,0 +1 @@
+sci-libs/linbox

build/pkgs/linbox/spkg-configure.m4

@@ -0,0 +1,8 @@
+SAGE_SPKG_CONFIGURE([linbox], [
+  SAGE_SPKG_DEPCHECK([fflas_ffpack flint fplll givaro gmp iml m4ri m4rie mpfr ntl], [
+    PKG_CHECK_MODULES([LINBOX],
+                      [linbox >= 1.6.3 linbox <= 1.6.4],
+                      [sage_spkg_install_linbox=no],
+                      [sage_spkg_install_linbox=yes])
+  ])
+])

build/pkgs/linbox/spkg-install.in

@@ -23,12 +23,6 @@ fi
 # See trac ticket #21221.
 LINBOX_CONFIGURE="--without-fplll $LINBOX_CONFIGURE"
 
-# Need to use 'bash' for configure, see
-# https://trac.sagemath.org/ticket/23451
-if [ -z "$CONFIG_SHELL" ]; then
-    export CONFIG_SHELL=`command -v bash`
-fi
-
 # We disable openmp because of build failures, see
 # http://trac.sagemath.org/ticket/17635#comment:67
 # We disable ocl because of build failures, see

build/pkgs/m4ri/distros/debian.txt

@@ -0,0 +1 @@
+libm4ri-dev