Do not pull in `sentry-actix` as default dependency

[Simon089]

Problem Statement

Starting with version 0.38.0 Sentry pulls in sentry-actix as a dependency by default, even without the actix feature flag. This installs a lot of crates around actix which are not used.

Solution Brainstorm

It looks like the default feature flag release-health pulls in sentry-actix since #788.
When adding the sentry crate with all default features but release-health the sentry-actix crate is not pulled in.

sentry = { version = "0.38.0", default-features = false, features = ["backtrace", "contexts", "debug-images", "panic", "transport"] }

Maybe the feature flag can be updated to fix this, not sure.

[lcian]

Hey, thank you so much for reporting.
We'll release a patch version ASAP.

[behnam-oneschema]

Thanks for the update, @lcian!

We're bumping to the 0.38.1 release now, but still see that the sentry package gets sentry-actix and actix-web family pulled in.

I tried disabling the default-features of sentry, then was able to verify that enabling release-health feature is triggering those dependencies to be added.

I should also note that, when release-health is enabled, cargo tree does NOT list any "actix" package in the tree. However, Cargo.lock still gets the actix-web package added, and any build starts by fetching actix-web and family.

So, I'm afraid this could be a side-effect of the package?/feature syntax and a possible short-coming of Cargo itself.

[lcian]

Yeah exactly @behnam-oneschema, it appears to be a side-effect of this syntax.
It's good to document it here in case anyone stumbles upon this issue.

The deps for sentry-actix will now still get pulled and included in your Cargo.lock, but not in your actual build.
You can test it also by building with just sentry as a dependency and default features (or just feature backtrace, really) and you will notice that tracing-core and tracing-subscriber are pulled in, because we have this line in the Cargo.toml:

backtrace = ["sentry-backtrace", "sentry-tracing?/backtrace"]

even though sentry-tracing is an optional dependency of sentry and is only activated when the tracing feature is turned on.