`cargo watch` to terminate the app when build process fails

In my typical development process I start from:

spin new -t http-rust -a example
cd example
spin watch

Then I alternately edit the code and test the app, e.g. using curl.

Whenever I make a mistake which results in compilation process failure, spin prints the error to stderr and keeps previous version of the app running. This requires me to constantly watch the output from spin or rely on IDE to highlight the problem. Otherwise I may end up testing outdated version of the code, which later leads to invalid reasoning.
The improvement that I would consider is terminating the app before starting compilation. This way any attempt of testing the app would reveal the compilation issue.

Start at the spin watch command and reproduce the issue with the http-rust template, editing the app until compilation fails. Verify that the running app is no longer available after the failure, rather than serving the previous version; no source file or test is named in the issue.