How to build unix port on macOS

[cdwilson]

I tried to build the unix port on macOS by following the directions at https://docs.micropython.org/en/latest/develop/gettingstarted.html#building-the-unix-port-of-micropython but I'm getting errors like this:

CC ../../lib/berkeley-db-1.xx/btree/bt_close.c
../../lib/berkeley-db-1.xx/btree/bt_close.c:63:1: error: a function declaration without a prototype is deprecated in all versions of C and is not supported in C2x [-Werror,-Wdeprecated-non-prototype]
__bt_close(dbp)
^
../../lib/berkeley-db-1.xx/btree/bt_close.c:116:1: error: a function declaration without a prototype is deprecated in all versions of C and is not supported in C2x [-Werror,-Wdeprecated-non-prototype]
__bt_sync(dbp, flags)
^
../../lib/berkeley-db-1.xx/btree/bt_close.c:159:1: error: a function declaration without a prototype is deprecated in all versions of C and is not supported in C2x [-Werror,-Wdeprecated-non-prototype]
bt_meta(t)
^
../../lib/berkeley-db-1.xx/btree/bt_close.c:159:1: error: a function declaration without a prototype is deprecated in all versions of C and is not supported in C2x [-Werror,-Wdeprecated-non-prototype]
4 errors generated.
-e See https://github.com/micropython/micropython/wiki/Build-Troubleshooting
make: *** [build-standard/lib/berkeley-db-1.xx/btree/bt_close.o] Error 1

It looks like it should be possible to build for macOS since I can brew install micropython. If someone has successfully built the unix port on macOS, could you walk me through the process?

[robert-hh]

You could try to build without the btree module by setting MICROPY_PY_BTREE = 0 in mpconfigport.mk.

[cdwilson]

@robert-hh thanks for the suggestion. I'm able to build the unix port by setting MICROPY_PY_BTREE = 0 in mpconfigport.mk as you suggested.

However, on the homebrew version of micropython, it looks like they were able to build with the btree module enabled:

❯ micropython
MicroPython v1.20.0 on 2023-04-26; darwin [GCC 4.2.1] version
Use Ctrl-D to exit, Ctrl-E for paste mode
>>> import btree
>>>

Looking at https://github.com/Homebrew/homebrew-core/blob/master/Formula/micropython.rb it's not obvious to me what they did differently when building this for macOS. I'm just doing the following (not sure if I'm missing some other mac-specific step?):

❯ cd ports/unix
❯ make submodules
❯ make

[jimmo]

Maybe homebrew compiles with an older version of gcc. (Edit: yes, see GCC 4.2.1 in the homebrew version's banner)

Either way, we probably need to add an exclusion for that warning -- we already have -Wno-old-style-definition in extmod/extmod.mk, sounds like we need to add -Wdeprecated-non-prototype. (Are you interested in sending a PR :) )

[cdwilson]

@jimmo thanks! you're right, that was it. Adding -Wno-deprecated-non-prototype fixes the build (see #11510 for PR)