gh-37011: allowing external ECM to be called gmp-ecm or ecm
    
ECM executable in Fedora is called `gmp-ecm`

This PR allows both names, `ecm` and `gmp-ecm`,  to be used
    
URL: #37011
Reported by: Dima Pasechnik
Reviewer(s): Dima Pasechnik, Enrique Manuel Artal Bartolo, Gonzalo Tornaría, Matthias Köppe, Michael Orlitzky, Tobias Diez

Author: Release Manager

build/pkgs/ecm/spkg-configure.m4

@@ -1,5 +1,6 @@
 SAGE_SPKG_CONFIGURE([ecm], [
     m4_pushdef([SAGE_ECM_MINVER],[7.0.4])
+    ECMBIN=ecm
     SAGE_SPKG_DEPCHECK([gmp], [
         AC_CHECK_HEADER(ecm.h, [
             AX_ABSOLUTE_HEADER([ecm.h])
@@ -18,20 +19,21 @@ SAGE_SPKG_CONFIGURE([ecm], [
                         AC_SEARCH_LIBS([ecm_factor], [ecm], [], [sage_spkg_install_ecm=yes])
                     ])
                 ])
-                AC_PATH_PROG([ECMBIN], [ecm])
-                if test x$ECMBIN != x; then
+                AC_PATH_PROGS([ECMBIN], [ecm gmp-ecm])
+                AS_IF([test x$ECMBIN != x], [
                     ecmbin_version=`echo 121 | $ECMBIN 4 | grep ^GMP |
                       $SED -n -e 's/GMP\-ECM \([[0-9]]*\.[[0-9]]*\.[[0-9]]*\).*/\1/p'`
-                fi
-                AS_IF([test -n "$ecmbin_version"], [
-                    AX_COMPARE_VERSION([$ecmbin_version], [ge], [$SAGE_ECM_MINVER], [
-                        ac_cv_ECMBIN="$ecmbin_version"
+                    AS_IF([test -n "$ecmbin_version"], [
+                        AX_COMPARE_VERSION([$ecmbin_version], [ge], [$SAGE_ECM_MINVER], [
+                          ac_cv_ECMBIN="$ecmbin_version"
+                        ])
                     ])
-                ])
+		], [ECMBIN=ecm])
             fi
             AS_IF([test -z "$ac_cv_ECM"], [sage_spkg_install_ecm=yes])
             AS_IF([test -z "$ac_cv_ECMBIN"], [sage_spkg_install_ecm=yes])
         ], [sage_spkg_install_ecm=yes])
     ])
     m4_popdef([SAGE_ECM_MINVER])
+    AC_SUBST(SAGE_ECMBIN, $ECMBIN)
 ])

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/features/ecm.py

@@ -0,0 +1,42 @@
+# -*- coding: utf-8 -*-
+r"""
+Feature for testing the presence of ``ecm`` or ``gmp-ecm``
+"""
+# ****************************************************************************
+#       Copyright (C) 2032 Dima Pasechnik <[email protected]>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 2 of the License, or
+# (at your option) any later version.
+#                  https://www.gnu.org/licenses/
+# ****************************************************************************
+
+from . import Executable
+from sage.env import SAGE_ECMBIN
+
+
+class Ecm(Executable):
+    r"""
+    A :class:`~sage.features.Feature` describing the presence of :ref:`GMP-ECM <spkg_ecm>`.
+
+    EXAMPLES::
+
+        sage: from sage.features.ecm import Ecm
+        sage: Ecm().is_present()
+        FeatureTestResult('ecm', True)
+    """
+    def __init__(self):
+        r"""
+        TESTS::
+
+            sage: from sage.features.ecm import Ecm
+            sage: isinstance(Ecm(), Ecm)
+            True
+        """
+        Executable.__init__(self, name="ecm", executable=SAGE_ECMBIN,
+                            spkg="ecm", type="standard")
+
+
+def all_features():
+    return [Ecm()]

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: