Warnings makes the project crash when installing on Debian Buster on BBB

[JeffLabonte]

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• Platform/operating system (i.e. Raspberry Pi with Raspbian operating system,
  Windows 32-bit, Windows 64-bit, Mac OSX 64-bit, etc.): debian buster

• Python version (run python -version or python3 -version): python 3.7.5

• Error message you are receiving, including any Python exception traces:
  The error is the same for a ARM device, in my case a BBB.

  ---

  x86_64-linux-gnu-gcc -pthread -Wno-unused-result -Wsign-compare -DNDEBUG -g -fwrapv -O2 -Wall -g -fstack-protector-strong -Wformat -Werror=format-security -g -fwrapv -O2 -g -fstack-protector-strong -Wformat -Werror=format-security -Wdate-time -D_FORTIFY_SOURCE=2 -fPIC -DBBBVERSION41 -Isource/include/ -I/usr/include/python3.7m -c source/py_gpio.c -o build/temp.linux-x86_64-3.7/source/py_gpio.o -Wall -Werror -Wextra -Wno-missing-field-initializers -Wno-strict-aliasing
  source/py_gpio.c:558:14: error: cast between incompatible function types from ‘PyObject * (*)(PyObject *, PyObject *, PyObject )’ {aka ‘struct _object * ()(struct _object *, struct _object *, struct _object )’} to ‘PyObject * ()(PyObject *, PyObject )’ {aka ‘struct _object * ()(struct _object *, struct _object )’} [-Werror=cast-function-type]
  558 | {"setup", (PyCFunction)py_setup_channel, METH_VARARGS | METH_KEYWORDS, "Set up the GPIO channel, direction and (optional) pull/up down control\nchannel - Either: RPi board pin number (not BCM GPIO 00..nn number). Pins start from 1\n or : BCM GPIO number\ndirection - INPUT or OUTPUT\n[pull_up_down] - PUD_OFF (default), PUD_UP or PUD_DOWN\n[initial] - Initial value for an output channel\n[delay] - Time in milliseconds to wait after exporting gpio pin"},
  | ^
  source/py_gpio.c:562:25: error: cast between incompatible function types from ‘PyObject * ()(PyObject *, PyObject *, PyObject )’ {aka ‘struct _object * ()(struct _object *, struct _object *, struct _object )’} to ‘PyObject * ()(PyObject *, PyObject )’ {aka ‘struct _object * ()(struct _object *, struct _object )’} [-Werror=cast-function-type]
  562 | {"add_event_detect", (PyCFunction)py_add_event_detect, METH_VARARGS | METH_KEYWORDS, "Enable edge detection events for a particular GPIO channel.\nchannel - either board pin number or BCM number depending on which mode is set.\nedge - RISING, FALLING or BOTH\n[callback] - A callback function for the event (optional)\n[bouncetime] - Switch bounce timeout in ms for callback"},
  | ^
  source/py_gpio.c:565:27: error: cast between incompatible function types from ‘PyObject * ()(PyObject *, PyObject *, PyObject )’ {aka ‘struct _object * ()(struct _object *, struct _object *, struct _object )’} to ‘PyObject * ()(PyObject *, PyObject )’ {aka ‘struct _object * ()(struct _object *, struct _object *)’} [-Werror=cast-function-type]
  565 | {"add_event_callback", (PyCFunction)py_add_event_callback, METH_VARARGS | METH_KEYWORDS, "Add a callback for an event already defined using add_event_detect()\ngpio - gpio channel\ncallback - a callback function\n[bouncetime] - Switch bounce timeout in ms"},
  | ^
  cc1: all warnings being treated as errors

---

• List the steps to reproduce the problem below (if possible attach code or commands
  to run): apt install build-essential python3-dev python3-smbus python3-pip && pip3 install Adafruit_BBIO

[silver2row]

Hello,

I am using Buster too. I have not been able to install the Adafruit-BBIO library just yet. I will return service when I figure out how.

Seth

[silver2row]

Hello Again,

See. This is my issue. It was on the machine, my BBBW, and then it just went away "magically." I am using Buster 4.19.x. I am backing up my files and directories now. I am starting w/ a fresh image.

...

It may be easier to restart than to fix a broken install but I just wanted to relay this info. in case you were thinking of still fixing the issue.

Seth

P.S. I have to bow out for now. I am sorry.

[pdp7]

I believe it is related to GCC flags:
Compiler error in gcc 8.2.0 on Debian 10.x (buster)
#308

I need to figure out how to have flags that work on both the new and old gcc.

[JeffLabonte]

I was able to compile the project when I removed the -Werror. Obviously, it isn't the way that I should operate and I am not sure if the library is going to work as expected ( It should, those are only warnings ).

[pdp7]

Refer to PR #321

[pdp7]

I am going to close this in favor of tracking this problem under issue #308

I believe I have a fix in PR #321