Ranging examples don't seem to work in release mode

[jamesmunns]

With a fairly recent nightly:

active toolchain
----------------

nightly-x86_64-unknown-linux-gnu (default)
rustc 1.32.0-nightly (6e9b84296 2018-11-10)

I am unable to get the examples working in --release builds. Normal builds work correctly, and I see the output.

I have a sneaking suspicion that nrf-rs/nrf-hal#33 is related, however I have tried this using the beta.4 release of nrf52832-hal, which contains fixes for this.

I also sometimes get errors that look like this via semihosting on the tag side: panicked at 'Failed to initialize DW1000: Spi(Transmit)', libcore/result.rs:1009:5

[jamesmunns]

Whoops. I had multiple copies of the dependencies locally. When actually using the changes in nrf-rs/nrf-hal#34, this now works in release mode.

Sorry for the noise, but I will keep this open until nrf-rs/nrf-hal#34 has landed upstream, and we have fixed our dependencies. This will probably be fixed naturally by landing #62.

[hannobraun]

Makes sense that the missing compiler fences would cause stuff to break in this way. Good to know your changes fix it!

[hannobraun]

Both nrf-rs/nrf-hal#34 and #62 have landed. The only thing required to close this issue for good would be to update the minimum version of the nrf52832-hal dependency to 0.6.1.

[hannobraun]

Now that this crate no longer depends on nrf52832-hal, this issue no longer belongs here. Opened hannobraun/rust-dwm1001#71.