Fixed sys features.

Before:
`sys` is compiled everytime if any of its features are set (e.g.
`no-exit`), even if the main crate is not `enabled`.

After:
`sys` is built only when the main crate is `enabled`.

It requires Rust 1.60, though.

CHANGELOG.md

@@ -12,12 +12,17 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 ### Removed
 
-## [Unreleased] - 2024-01-xx
+## [Unreleased] - 2024-xx-xx
 
 ### Added
 
 - `#[capture]` attribute to instrument main added.
 
+### Fixed
+
+- `sys` is no longer compiled when we are not `enabled`, but some
+  other features are set (e.g. `no-exit`).
+
 ### Changed
 
 - minor example updates

tracy-gizmos/Cargo.toml

@@ -29,18 +29,18 @@ enabled                 = ["dep:sys", "only-localhost"]
 unstable-function-names = []
 attributes              = ["dep:attrs"]
 # sys features
-crash-handler           = ["sys/crash-handler"]
-system-tracing          = ["sys/system-tracing"]
-context-switch          = ["sys/context-switch"]
-sampling                = ["sys/sampling"]
-callstack-inlines       = ["sys/callstack-inlines"]
-hw-counters             = ["sys/hw-counters"]
-code-transfer           = ["sys/code-transfer"]
-vsync                   = ["sys/vsync"]
-no-exit                 = ["sys/no-exit"]
-broadcast               = ["sys/broadcast"]
-only-localhost          = ["sys/only-localhost"]
-only-ipv4               = ["sys/only-ipv4"]
+crash-handler           = ["sys?/crash-handler"]
+system-tracing          = ["sys?/system-tracing"]
+context-switch          = ["sys?/context-switch"]
+sampling                = ["sys?/sampling"]
+callstack-inlines       = ["sys?/callstack-inlines"]
+hw-counters             = ["sys?/hw-counters"]
+code-transfer           = ["sys?/code-transfer"]
+vsync                   = ["sys?/vsync"]
+no-exit                 = ["sys?/no-exit"]
+broadcast               = ["sys?/broadcast"]
+only-localhost          = ["sys?/only-localhost"]
+only-ipv4               = ["sys?/only-ipv4"]
 
 [package.metadata.docs.rs]
 all-features = true