If you are using STM32 and are receiving errors when you try to cargo run --release, please check the following:

• You are specifying the correct --chip on the command line, OR
• You have set .cargo/config.toml's run line to the correct chip, AND
• You have changed examples//Cargo.toml's embassy-stm32 dependency's feature to use the correct chip (replace the existing stm32xxxx feature)
• At this point the project should run. If you do not see a blinky LED for blinky, for example, be sure to check the code is toggling your board's LED pin.

If you are trying to run an example with cargo run --release and you see the following output:

0.000000 INFO Hello World!
└─ <invalid location: defmt frame-index: 14>
0.000000 DEBUG rcc: Clocks { sys: Hertz(80000000), apb1: Hertz(80000000), apb1_tim: Hertz(80000000), apb2: Hertz(80000000), apb2_tim: Hertz(80000000), ahb1: Hertz(80000000), ahb2: Hertz(80000000), ahb3: Hertz(80000000) }
└─ <invalid location: defmt frame-index: 124>
0.000061 TRACE allocating type=Interrupt mps=8 interval_ms=255, dir=In
└─ <invalid location: defmt frame-index: 68>
0.000091 TRACE   index=1
└─ <invalid location: defmt frame-index: 72>

To get rid of the frame-index error add the following to your Cargo.toml:

[profile.release]
debug = 2