Multiple variations on cargo config

[anthonyjmartinez]

Prior to ch. 7 on Registers, each chapter by default uses the overall project's default src/.cargo/config.toml, which some chapters suggest modifying to use your platform's specific gdb.

This is overridden for the first time in Ch 7 by an unmentioned src/07-registers/.cargo/config with a default assumption that arm-none-eabi-gdb is to be used. In my case, no such gdb exists, and cargo run fails. Editing as follows allowed me to continue, but some may not understand the resulting error from Cargo well enough (or realize that you can have a multitude of .cargo/config or .cargo/config.toml files) to fix the issue:

diff --git a/src/07-registers/.cargo/config b/src/07-registers/.cargo/config
index f5a1d95..e11ff2f 100644
--- a/src/07-registers/.cargo/config
+++ b/src/07-registers/.cargo/config
@@ -1,5 +1,5 @@
 [target.thumbv7em-none-eabihf]
-runner = "arm-none-eabi-gdb -q -x openocd.gdb"
+runner = "gdb -q -x openocd.gdb"
 #rustflags = [
 #  "-C", "link-arg=-Tlink.x",
 #]

Maybe it's worth adding a helpful note in chapters where a custom config exists so users know exactly what to modify to get back to a working state?

[user@projects discovery]$ find . -type f -wholename "*/.cargo/config*" | sort
./src/.cargo/config.toml
./src/07-registers/.cargo/config
./src/08-leds-again/.cargo/config
./src/09-clocks-and-timers/.cargo/config
./src/11-usart/.cargo/config
./src/14-i2c/.cargo/config
./src/15-led-compass/.cargo/config
./src/16-punch-o-meter/.cargo/config
./src/WIP-async-io-the-future/.cargo/config

[eldruin]

Hmm, I guess those are left overs not removed in #308.
@winksaville is there any reason why those config files other than ./src/.cargo/config.toml should stay?

[yoloVoe]

I deleted the .cargo directory under f3discovery/src/07-registers, and now cargo run is successfully using the appropriate config from f3discovery/src/.cargo.