Merge pull request #3470 from jsiirola/gurobi-12-nl

Update Gurobi NL interface for Gurobi 12.x

pyomo/solvers/plugins/solvers/GUROBI.py

@@ -87,7 +87,28 @@ def __new__(cls, *args, **kwds):
         else:
             logger.error('Unknown IO type: %s' % mode)
             return
-        opt.set_options('solver=gurobi_ampl')
+        # The Gurobi ASL solver was 'gurobi_ampl' through Gurobi 11,
+        # then was renamed to 'gurobi'.  Check 'gurobi' first, then
+        # 'gurobi_ampl'.
+        for exe_name in ('gurobi', 'gurobi_ampl'):
+            exe = Executable(exe_name)
+            if (
+                exe.available()
+                and b'[-AMPL]'
+                in subprocess.run(
+                    exe.executable,
+                    stdin=subprocess.DEVNULL,
+                    stdout=subprocess.PIPE,
+                    stderr=subprocess.PIPE,
+                    timeout=1,
+                ).stdout
+            ):
+                opt.set_options(f'solver={exe_name}')
+                break
+        else:
+            # Fall back on 'gurobi' (matching the current Gurobi
+            # release) if neither appears to be available.
+            opt.set_options('solver=gurobi')
         return opt