Rumprun doesn't build on NetBSD 7.1

[yarwelp]

./build-rr.sh hw

[...]

>> Rump kernel components built.  Proceeding to build
>> rumprun bits
>>
make: "/home/yarwelp/rumprun/app-tools/Makefile" line 1: Missing dependency operator
make: "/home/yarwelp/rumprun/app-tools/Makefile" line 2: Need an operator
make: "/home/yarwelp/rumprun/app-tools/Makefile" line 3: Need an operator
make: "/home/yarwelp/rumprun/app-tools/Makefile" line 6: Missing dependency operator
make: "/home/yarwelp/rumprun/app-tools/Makefile" line 7: Need an operator
make: "/home/yarwelp/rumprun/app-tools/Makefile" line 8: Need an operator
make: "/home/yarwelp/rumprun/app-tools/Makefile" line 29: Missing dependency operator
make: "/home/yarwelp/rumprun/app-tools/Makefile" line 32: Need an operator
make: "../../global.mk" line 1: Missing dependency operator
make: "../../global.mk" line 2: Need an operator
make: "../../global.mk" line 3: Need an operator
make: "../../global.mk" line 5: Missing dependency operator
make: "../../global.mk" line 6: Need an operator
make: "../../global.mk" line 7: Need an operator
make: "../../global.mk" line 15: Need an operator
make: "../../global.mk" line 17: Need an operator
make: "../../global.mk" line 21: Missing dependency operator
make: "../../global.mk" line 23: Need an operator
make: "../../global.mk" line 25: Need an operator
Variable MACHINE_GNU_PLATFORM is recursive.

make: stopped in /home/yarwelp/rumprun/app-tools
${MAKE_PRINT_VAR_ON_ERROR:@v@$v='${$v}'

[lin7sh]

seems like you need gmake