Raise minimum Rust version to 1.51, de-vendor openssl on unix

Rust 1.51 allows addressesing a long-standing TODO which was that we
shouldn't need to build a vendored copy of openssl on most sensible unix
systems.

We do require a vendored copy on macOS and Windows, but due to the way
that Cargo's feature resolver worked, it wasn't possible for this
requirement to be respected.

Rust 1.51 introduces `resolver="2"` which can deal with this feature
resolution!

https://doc.rust-lang.org/nightly/cargo/reference/features.html#feature-resolver-version-2

The upshot of this is that building wezterm on real unix systems that
are not macos will now link against the system libssl, resulting in both
a shorter compile time and less headaches arising from having a slightly
different openssl used by wezterm than the rest of the system.

cc: @jsgf

Cargo.lock

@@ -4464,7 +4464,6 @@ dependencies = [
  "mlua",
  "mux",
  "open",
- "openssl",
  "ordered-float",
  "palette",
  "portable-pty",

Cargo.toml

@@ -1,5 +1,6 @@
 [workspace]
 members = ["wezterm-mux-server", "wezterm", "wezterm-gui", "strip-ansi-escapes", "wezterm-ssh"]
+resolver = "2"
 
 [profile.release]
 opt-level = 3

async_ossl/Cargo.toml

@@ -3,8 +3,13 @@ name = "async_ossl"
 version = "0.1.0"
 authors = ["Wez Furlong <wez@wezfurlong.org>"]
 edition = "2018"
+resolver = "2"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
-[dependencies]
+[target.'cfg(not(any(windows, target_os="macos")))'.dependencies]
 openssl = "0.10"
+
+[target.'cfg(any(windows, target_os="macos"))'.dependencies]
+openssl = { version = "0.10", features=["vendored"] }
+

docs/install/source.markdown

@@ -6,7 +6,7 @@ macOS.
 
 * Install `rustup` to get the `rust` compiler installed on your system.
   [Install rustup](https://www.rust-lang.org/en-US/install.html)
-* Rust version 1.41 or later is required
+* Rust version 1.51 or later is required
 * Build in release mode: `cargo build --release`
 * Run it via either `cargo run --release --bin wezterm` or `target/release/wezterm`
 

wezterm-gui/Cargo.toml

@@ -4,6 +4,7 @@ version = "0.1.0"
 authors = ["Wez Furlong <wez@wezfurlong.org>"]
 edition = "2018"
 build = "build.rs"
+resolver = "2"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
@@ -36,7 +37,6 @@ metrics = { version="0.14", features=["std"]}
 mlua = "0.5"
 mux = { path = "../mux" }
 open = "1.4"
-openssl = "0.10"
 ordered-float = "2.1"
 palette = "0.5"
 portable-pty = { path = "../pty", features = ["serde_support", "ssh"]}
@@ -82,11 +82,6 @@ winapi = { version = "0.3", features = [
     "winsock2",
 ]}
 
-[features]
-default = ["vendor_openssl"]
-# FIXME: find a way to magically disable vendor_openssl only on linux!
-vendor_openssl = ["openssl/vendored"]
-
 [dev-dependencies]
 k9 = "0.10.0"
 pretty_env_logger = "0.4"

wezterm-mux-server/Cargo.toml

@@ -3,6 +3,7 @@ name = "wezterm-mux-server"
 version = "0.1.0"
 authors = ["Wez Furlong <wez@wezfurlong.org>"]
 edition = "2018"
+resolver = "2"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
@@ -25,7 +26,3 @@ wezterm-gui-subcommands = { path = "../wezterm-gui-subcommands" }
 [target."cfg(windows)".dependencies]
 winapi = { version = "0.3", features = [ "winuser" ]}
 
-[features]
-default = ["vendor_openssl"]
-# FIXME: find a way to magically disable vendor_openssl only on linux!
-vendor_openssl = ["openssl/vendored"]