`esp32-led-strip-sdk` crash on ESP32-C6 , cannot use `.random`

[gerwindehaan]

I experience a crash/bootloop on the esp32-led-strip-sdk example when run on my ESP32-C6

I traced it down to the use of .random in the led strip color generation (it works if I avoid that). The behavior is illustrated by the following minimal snippet:

@_cdecl("app_main")
func app_main() {
  print("Running Int.random")  
  let _ = Int.random(in: 0...16)
  print(". ")
  while(true){ }
}

Running this on device causes a crash when the .random is invoked, followed by a reboot. When compiling this sample (or anything where .random is spawned, a warning is spawned around _getentropy:

[5/7] Linking CXX executable main.elf
/Users/gerwindehaan/.espressif/tools/riscv32-esp-elf/esp-13.2.0_20240305/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/13.2.0/../../../../riscv32-esp-elf/bin/ld: /Users/gerwindehaan/.espressif/tools/riscv32-esp-elf/esp-13.2.0_20240305/riscv32-esp-elf/bin/../lib/gcc/riscv32-esp-elf/13.2.0/../../../../riscv32-esp-elf/lib/rv32imac_zicsr_zifencei/ilp32/no-rtti/libc.a(libc_a-getentropyr.o): in function `_getentropy_r':
/builds/idf/crosstool-NG/.build/HOST-x86_64-apple-darwin21.1/riscv32-esp-elf/src/newlib/newlib/libc/reent/getentropyr.c:48:(.text+0x16): warning: _getentropy is not implemented and will always fail

I am wondering if this has to do with my configuration of the device, or that I should somehow enable the random generator RNG when Wifi/BLE are off .

[erhankur]

We have shared the patch here https://github.com/apple/swift-embedded-examples/issues/17#issuecomment-2174479217

[gerwindehaan]

Thanks, after applying this patch to my esp-idf source solves the issue with .random and the sample works as advertised. Closing as this is tracked by https://github.com/apple/swift-embedded-examples/issues/17 and https://github.com/apple/swift-matter-examples/issues/5