Since #2123, user of PIO have an error:
0ffbf3e#commitcomment-126862592

error: a label can only be part of a statement and a declaration is not a statement

After some test, I've been able to reproduce within Arduino by downgrading the arm-none-eab-gcc version used from 12.2.1 to 10.3.1
PIO uses arm-non-eabi-gcc 10.3.1 while Arduino used 12.2.1.
A request was made to update it:
platformio/platform-ststm32#720
Seems it brings some issues with gdb anyway it seems user can update it manually.

Nevertheless, I guess the code could be update to avoid this.

/cc @ellensp