allowing external ECM to be called gmp-ecm, not ecm

This is how it is called in Fedora

Author: dimpase

build/pkgs/ecm/spkg-configure.m4

@@ -1,5 +1,6 @@
 SAGE_SPKG_CONFIGURE([ecm], [
     m4_pushdef([SAGE_ECM_MINVER],[7.0.4])
+    SAGE_ECM_BIN=ecm
     SAGE_SPKG_DEPCHECK([gmp], [
         AC_CHECK_HEADER(ecm.h, [
             AX_ABSOLUTE_HEADER([ecm.h])
@@ -18,8 +19,9 @@ SAGE_SPKG_CONFIGURE([ecm], [
                         AC_SEARCH_LIBS([ecm_factor], [ecm], [], [sage_spkg_install_ecm=yes])
                     ])
                 ])
-                AC_PATH_PROG([ECMBIN], [ecm])
+                AC_PATH_PROGS([ECMBIN], [ecm gmp-ecm])
                 if test x$ECMBIN != x; then
+                    SAGE_ECM_BIN=`basename $ECMBIN`
                     ecmbin_version=`echo 121 | $ECMBIN 4 | grep ^GMP |
                       $SED -n -e 's/GMP\-ECM \([[0-9]]*\.[[0-9]]*\.[[0-9]]*\).*/\1/p'`
                 fi
@@ -34,4 +36,5 @@ SAGE_SPKG_CONFIGURE([ecm], [
         ], [sage_spkg_install_ecm=yes])
     ])
     m4_popdef([SAGE_ECM_MINVER])
+    AC_SUBST(SAGE_ECMBIN, $SAGE_ECM_BIN)
 ])

pkgs/sage-conf/_sage_conf/_conf.py.in

@@ -32,6 +32,8 @@ ECL_CONFIG = "@SAGE_ECL_CONFIG@".replace('${prefix}', SAGE_LOCAL)
 
 SAGE_NAUTY_BINS_PREFIX = "@SAGE_NAUTY_BINS_PREFIX@"
 
+SAGE_ECMBIN = "@SAGE_ECMBIN@"
+
 # Names or paths of the 4ti2 executables
 FOURTITWO_HILBERT = "@FOURTITWO_HILBERT@"
 FOURTITWO_MARKOV = "@FOURTITWO_MARKOV@"

src/sage/env.py

@@ -220,6 +220,7 @@ def var(key: str, *fallbacks: Optional[str], force: bool = False) -> Optional[st
 MAXIMA_FAS = var("MAXIMA_FAS")
 KENZO_FAS = var("KENZO_FAS")
 SAGE_NAUTY_BINS_PREFIX = var("SAGE_NAUTY_BINS_PREFIX", "")
+SAGE_ECMBIN = var("SAGE_ECMBIN")
 RUBIKS_BINS_PREFIX = var("RUBIKS_BINS_PREFIX", "")
 FOURTITWO_HILBERT = var("FOURTITWO_HILBERT")
 FOURTITWO_MARKOV = var("FOURTITWO_MARKOV")

src/sage/interfaces/ecm.py

@@ -55,6 +55,7 @@
 from sage.structure.sage_object import SageObject
 from sage.rings.integer_ring import ZZ
 
+from sage.env import SAGE_ECMBIN
 
 class ECM(SageObject):
 
@@ -182,7 +183,7 @@ def __init__(self, B1=10, B2=None, **kwds):
         self._cmd = self._make_cmd(B1, B2, kwds)
 
     def _make_cmd(self, B1, B2, kwds):
-        ecm = ['ecm']
+        ecm = [SAGE_ECMBIN]
         options = []
         for x, v in kwds.items():
             if v is False: