"item constrains opaque type that is not in its signature" for rtic 2.0.0

[Guo Weixuan]

I am trying to run the stm32f3_blinky example in Windows. However, after I change my rust toolchain to nightly, there will be the following error:

error: item constrains opaque type that is not in its signature
--> src\main.rs:14:1
|
14 | #[app(device = stm32f3xx_hal::pac, peripherals = true, dispatchers = [SPI1])]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: this item must mention the opaque type in its signature in order to be able to register hidden types
note: this item must mention the opaque type in its signature in order to be able to register hidden types
--> src\main.rs:14:1
|
14 | #[app(device = stm32f3xx_hal::pac, peripherals = true, dispatchers = [SPI1])]
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
= note: this error originates in the attribute macro app (in Nightly builds, run with -Z macro-backtrace for more info)

error: could not compile stm32f3-blinky (bin "stm32f3-blinky") due to previous error

[David Goodlad]

I just hit this same issue; while I haven't had time to track it down to a specific commit or feature in nightly, I did confirm that nightly-2023-07-08 works while nightly-2023-07-09 is broken.

[Henrik Tjäder]

This issue was discussed in depth during this week's meeting. @korken89 will investigate further

Start of discussion:
https://matrix.to/#/!yafYEipFNsXDdwiHMT:matrix.org/$FuzFTd8VcVaMtzNr2F8j8Ni3whBEjWtf27ym1zM9Yj0?via=matrix.org&via=kde.org&via=tchncs.de