Require gmake in python bindings build for FreeBSD

Makefile

@@ -3,11 +3,11 @@ all: c csharp elixir go java nim nodejs python rust
 
 .PHONY: c
 c:
-	@make -C src
+	@$(MAKE) -C src
 
 .PHONY: csharp
 csharp:
-	@make -C bindings/csharp
+	@$(MAKE) -C bindings/csharp
 
 .PHONY: elixir
 elixir:
@@ -19,19 +19,19 @@ go:
 
 .PHONY: java
 java:
-	@make -C bindings/java build test
+	@$(MAKE) -C bindings/java build test
 
 .PHONY: nim
 nim:
 	@cd bindings/nim && nim test
 
 .PHONY: nodejs
 nodejs:
-	@make -C bindings/node.js
+	@$(MAKE) -C bindings/node.js
 
 .PHONY: python
 python:
-	@make -C bindings/python
+	@$(MAKE) -C bindings/python
 
 .PHONY: rust
 rust:

setup.py

@@ -1,19 +1,31 @@
-from os import chdir
+from os import chdir, environ
 from pathlib import Path
 from platform import system
+from shutil import which
 from setuptools import setup, Extension
 from setuptools.command.build_ext import build_ext
 from subprocess import check_call
 
 
+def get_make():
+    """Get the GNU make command. Honors $MAKE if set."""
+    if "MAKE" in environ:
+        return environ["MAKE"]
+    if system() == "FreeBSD":
+        if not which("gmake"):
+            raise RuntimeError("GNU make (gmake) is required on FreeBSD")
+        return "gmake"
+    return "make"
+
+
 class CustomBuild(build_ext):
     def run(self):
         if system() == "Windows":
             try:
                 check_call(["blst\\build.bat"])
             except Exception:
                 pass
-        check_call(["make", "-C", "src", "blst"])
+        check_call([get_make(), "-C", "src", "blst"])
         super().run()