build(next/core): allow to specify tls backend for reqwest (vercel/tu…

…rbo#2994)

Implement / fixes WEB-306.

We can't rely on default tls backend for reqwest and hope to work with
every target platform we support, due to several constraints. Some
target cannot use -sys (openssl-sys), and some can't build rustls due to
trasnsitive dep support issue.

PR creates explicit opt-in features for those and let upstream
application can specify what they need. `next-dev` currently sets
`native-tls` as default for the general dev workflow conveniences, but
that doesn't mean we promote it as default feature set - next-swc, or
other like standalone turbopack will configure features by themselves
when build binaries for their own.

packages/next-swc/crates/next-core/Cargo.toml

@@ -35,3 +35,5 @@ turbo-tasks-build = { path = "../turbo-tasks-build" }
 
 [features]
 next-font-local = []
+native-tls = ["turbo-tasks-fetch/native-tls"]
+rustls-tls = ["turbo-tasks-fetch/rustls-tls"]

packages/next-swc/crates/next-dev/Cargo.toml

@@ -19,7 +19,12 @@ name = "mod"
 harness = false
 
 [features]
-default = ["cli", "custom_allocator"]
+# By default, we enable native-tls for reqwest downstream trasntive features.
+# This is for the convinience for all of daily dev workflow i.e running
+# `cargo xxx` without explicitly specifying features, not that we want to
+# promote this as default backend. Actual configuration is done when build next-swc,
+# and also turbopack standalone when we have it.
+default = ["cli", "custom_allocator", "native-tls"]
 cli = []
 serializable = []
 tokio_console = [
@@ -30,6 +35,8 @@ tokio_console = [
 profile = []
 custom_allocator = ["turbo-malloc/custom_allocator"]
 next-font-local = ["next-core/next-font-local"]
+native-tls = ["next-core/native-tls"]
+rustls-tls = ["next-core/rustls-tls"]
 
 [dependencies]
 anyhow = "1.0.47"