Update to c-gull 0.20.3. (#56)

And remove the "unwinding" workaround.

Cargo.toml

@@ -13,7 +13,7 @@ exclude = ["/.github", "ci"]
 keywords = ["linux"]
 
 [dependencies]
-c-gull = { version = "0.20.0", default-features = false, features = ["eyra"] }
+c-gull = { version = "0.20.3", default-features = false, features = ["eyra"] }
 
 [dev-dependencies]
 assert_cmd = "2.0.12"
@@ -27,7 +27,7 @@ rand_xorshift = "0.3.0"
 ctor = "0.2.0"
 
 # Check if rustup is installed for tests
-which = "6.0.0"
+which = "7.0.0"
 
 # Test that the core_simd crate works under eyra.
 # TODO: Reenable this when the crate compiles on nightly. Currently it gets:

README.md

@@ -166,11 +166,6 @@ Hello, world!
 
 ## Compatibility with `-Zbuild-std`
 
-At this time, a combination of Eyra, `-Zbuild-std`, and `panic = "abort"` does
-not work. See [nbdd0121/unwinding#39] for details. FIXME.
-
-[nbdd0121/unwinding#39]: https://github.com/nbdd0121/unwinding/issues/39
-
 Eyra works with `-Zbuild-std`, however the `--rename=std` trick used above
 doesn't work, so it's necessary to instead use this `cargo add` invocation:
 

example-crates/hello-world-small/Cargo.toml

@@ -13,9 +13,7 @@ strip = true  # Automatically strip symbols from the binary.
 opt-level = "z"  # Optimize for size.
 lto = true
 codegen-units = 1
-# FIXME: `panic = "abort"` does not currently work with `-Zbuild-std` due
-# to <https://github.com/nbdd0121/unwinding/issues/39>.
-#panic = "abort"
+panic = "abort"
 
 # This is just an example crate, and not part of the eyra workspace.
 [workspace]

tests/example_crates.rs

@@ -75,10 +75,8 @@ fn example_crate_hello_world_small() {
         "hello-world-small",
         &[
             "--release",
-            // FIXME: When nbdd0121/unwinding#39 is fixed, this should be
-            // "-Zbuild-std=std,panic_abort",
-            // "-Zbuild-std-features=panic_immediate_abort",
-            "-Zbuild-std",
+            "-Zbuild-std=std,panic_abort",
+            "-Zbuild-std-features=panic_immediate_abort",
         ],
         &[(
             "RUSTFLAGS",