Failed attempt to rename spec `link_gcc_c_sequence` to `nosys_link_gcc_c_sequence`

[khoi-nguyen-2359]

Hello all.

I run into this error when compiling the source code. In short, the nosys_link_gcc_c_sequence somehow already existed when executing nosys.specs.

Error logs:

➜  crazyflie-firmware git:(develop) ✗ make cf2_defconfig
...
➜  crazyflie-firmware git:(develop) ✗ make -j$(sysctl -n hw.ncpu)
  GEN     ./Makefile
scripts/kconfig/conf  --silentoldconfig Kconfig
  Using .. as source for kernel
  GEN     ./Makefile
  LD      app_api/built-in.o
  CC      src/init/main.o
 ...
  LD      src/init/built-in.o
arm-none-eabi-gcc: fatal error: /Applications/ArmGNUToolchain/14.3.rel1/arm-none-eabi/bin/../lib/gcc/arm-none-eabi/14.3.1/../../../../arm-none-eabi/lib/nosys.specs: attempt to rename spec 'link_gcc_c_sequence' to already defined spec 'nosys_link_gcc_c_sequence'
compilation terminated.
make[3]: *** [src/init/built-in.o] Error 1
make[2]: *** [src/init] Error 2
make[2]: *** Waiting for unfinished jobs....
  CC      src/drivers/esp32/src/esp_rom_bootloader.o
...

Environment: MacOS / Apple Silicon
ARM toolchain: 14.3.rel1 (Same issues with 12.2 and 13.3)

Workaround: Removing two-- specs in LDFLAGS (issues with nano.specs too) can get the compile to succeed.

-LDFLAGS += --specs=nosys.specs --specs=nano.specs $(PROCESSOR) -nostdlib
+LDFLAGS += $(PROCESSOR) -nostdlib

My question is, when is the nosys_link_gcc_c_sequence created the first time? LDFLAGS in Makefile seems to be the only place showing that the specs are specified. However, I notice that nosys and nano specs are also used in vendor/CMSIS/CMSIS/DSP/Toolchain/GCC.cmake.

Thank you!

[ataffanel]

Hi! How did you install the toolchain? This is not something I have ever seen on my side. I have had success installing the toolchain with brew.

When you get the compilation to succeed, does the firmware seems to work properly?

[khoi-nguyen-2359]

Hi @ataffanel ,

I followed the building and flashing guide: brew install gcc-arm-embedded , and get version 14.3.
After failing attempts, I use different versions from ARM GNU Toolchain, but the issue persists.

I haven’t had a chance to flash, so I’ll update it later.

Can you suggest a common settings that should have no problems, like OS (Linux/Windows/MacOS), toolchain version?

Appreciate your support!

[ataffanel]

Hi,

This is quite odd, on my M1 mac on MacOS 26 with arm-embedded 14.3 Rel1 installed with brew, it woks fine.

The most maintain platform is Linux since this is what all the developers are using at Bitcraze.

[khoi-nguyen-2359]

@ataffanel
There’s an issue with my LDFLAGS when it has a predefined value in .zshrc:

# In ~/.zshrc:
export LDFLAGS=“-L/some/lib"

I created a task to print this flag’s content in the Makefile:

# Makefile
print_flags:
	@echo "=== LDFLAGS ==="
	@echo "$(LDFLAGS)"

The output somehow gets doubled:

crazyflie-firmware@ make print_flags
tools/kbuild/Makefile.kbuild:147: warning: overriding commands for target `print_flags'
Makefile:207: warning: ignoring old commands for target `print_flags'
=== LDFLAGS ===
-L/some/lib --specs=nosys.specs --specs=nano.specs -mcpu=cortex-m4 -mthumb -mfloat-abi=hard -mfpu=fpv4-sp-d16 -nostdlib --specs=nosys.specs --specs=nano.specs -mcpu=cortex-m4 -mthumb -mfloat-abi=hard -mfpu=fpv4-sp-d16 -nostdlib

When I clear the zshrc config, LDFLAGS seems to be normally constructed:

crazyflie-firmware@ make print_flags
tools/kbuild/Makefile.kbuild:147: warning: overriding commands for target `print_flags'
Makefile:207: warning: ignoring old commands for target `print_flags'
=== LDFLAGS ===
--specs=nosys.specs --specs=nano.specs -mcpu=cortex-m4 -mthumb -mfloat-abi=hard -mfpu=fpv4-sp-d16 -nostdlib

TheLDFLAGS's content might not be the cause, but only after this change the build on my machine no longer has problems with nosys.specs. Turns out there’s no issue with OS or compiler versions.

Thank you for looking into this! 🙏

[ataffanel]

Glad that you found the problem! Generally speaking setting LDFLAGS in you .zshrc is not a good idea since it is very common for makefiles to accept flags from the system environment variable.