From 0ea12c3c5fd218671ae42a99757a332fba8597cc Mon Sep 17 00:00:00 2001 From: Jieyou Xu Date: Mon, 26 May 2025 00:04:20 +0800 Subject: [PATCH] cfg_version: pull out dedicated syntax test from feature gate test The feature gate test was dual-purposing causing feature gate errors to distract from syntax exercises. --- tests/ui/cfg/cfg-version/syntax.rs | 152 +++++++++++++ tests/ui/cfg/cfg-version/syntax.stderr | 188 ++++++++++++++++ .../feature-gates/feature-gate-cfg-version.rs | 49 +---- .../feature-gate-cfg-version.stderr | 204 +----------------- 4 files changed, 350 insertions(+), 243 deletions(-) create mode 100644 tests/ui/cfg/cfg-version/syntax.rs create mode 100644 tests/ui/cfg/cfg-version/syntax.stderr diff --git a/tests/ui/cfg/cfg-version/syntax.rs b/tests/ui/cfg/cfg-version/syntax.rs new file mode 100644 index 0000000000000..22aab47e1ecdf --- /dev/null +++ b/tests/ui/cfg/cfg-version/syntax.rs @@ -0,0 +1,152 @@ +//! Check `#[cfg(version(..))]` parsing. + +#![feature(cfg_version)] + +// Overall grammar +// =============== +// +// `#[cfg(version(..))]` accepts only the `version(VERSION_STRING_LITERAL)` predicate form, where +// only a single string literal is permitted. + +#[cfg(version(42))] +//~^ ERROR expected a version literal +fn not_a_string_literal_simple() {} + +#[cfg(version(1.20))] +//~^ ERROR expected a version literal +fn not_a_string_literal_semver_like() {} + +#[cfg(version(false))] +//~^ ERROR expected a version literal +fn not_a_string_literal_other() {} + +#[cfg(version("1.43", "1.44", "1.45"))] +//~^ ERROR expected single version literal +fn multiple_version_literals() {} + +// The key-value form `cfg(version = "..")` is not considered a valid `cfg(version(..))` usage, but +// it will only trigger the `unexpected_cfgs` lint and not a hard error. + +#[cfg(version = "1.43")] +//~^ WARN unexpected `cfg` condition name: `version` +fn key_value_form() {} + +// Additional version string literal constraints +// ============================================= +// +// The `VERSION_STRING_LITERAL` ("version literal") has additional constraints on its syntactical +// well-formedness. + +// 1. A valid version literal can only constitute of numbers and periods (a "simple" semver version +// string). Non-semver strings or "complex" semver strings (such as build metadata) are not +// considered valid version literals, and will emit a non-lint warning "unknown version literal +// format". + +#[cfg(version("1.43.0"))] +fn valid_major_minor_patch() {} + +#[cfg(version("0.0.0"))] +fn valid_zero_zero_zero_major_minor_patch() {} + +#[cfg(version("foo"))] +//~^ WARN unknown version literal format, assuming it refers to a future version +fn not_numbers_or_periods() {} + +#[cfg(version("1.20.0-stable"))] +//~^ WARN unknown version literal format, assuming it refers to a future version +fn complex_semver_with_metadata() {} + +// 2. "Shortened" version strings are permitted but *only* for the omission of the patch number. + +#[cfg(version("1.0"))] +fn valid_major_minor_1() {} + +#[cfg(version("1.43"))] +fn valid_major_minor_2() {} + +#[cfg(not(version("1.44")))] +fn valid_major_minor_negated_smoke_test() {} + +#[cfg(version("0.0"))] +fn valid_zero_zero_major_minor() {} + +#[cfg(version("0.7"))] +fn valid_zero_major_minor() {} + +// 3. Major-only, or other non-Semver-like strings are not permitted. + +#[cfg(version("1"))] +//~^ WARN unknown version literal format, assuming it refers to a future version +fn invalid_major_only() {} + +#[cfg(version("0"))] +//~^ WARN unknown version literal format, assuming it refers to a future version +fn invalid_major_only_zero() {} + +#[cfg(version(".7"))] +//~^ WARN unknown version literal format, assuming it refers to a future version +fn invalid_decimal_like() {} + +// Misc parsing overflow/underflow edge cases +// ========================================== +// +// Check that we report "unknown version literal format" user-facing warnings and not ICEs. + +#[cfg(version("-1"))] +//~^ WARN unknown version literal format, assuming it refers to a future version +fn invalid_major_only_negative() {} + +// Implementation detail: we store rustc version as `{ major: u16, minor: u16, patch: u16 }`. + +#[cfg(version("65536"))] +//~^ WARN unknown version literal format, assuming it refers to a future version +fn exceed_u16_major() {} + +#[cfg(version("1.65536.0"))] +//~^ WARN unknown version literal format, assuming it refers to a future version +fn exceed_u16_minor() {} + +#[cfg(version("1.0.65536"))] +//~^ WARN unknown version literal format, assuming it refers to a future version +fn exceed_u16_patch() {} + +#[cfg(version("65536.0.65536"))] +//~^ WARN unknown version literal format, assuming it refers to a future version +fn exceed_u16_mixed() {} + +// Usage as `cfg!()` +// ================= + +fn cfg_usage() { + assert!(cfg!(version("1.0"))); + assert!(cfg!(version("1.43"))); + assert!(cfg!(version("1.43.0"))); + + assert!(cfg!(version("foo"))); + //~^ WARN unknown version literal format, assuming it refers to a future version + assert!(cfg!(version("1.20.0-stable"))); + //~^ WARN unknown version literal format, assuming it refers to a future version + + assert!(cfg!(version = "1.43")); + //~^ WARN unexpected `cfg` condition name: `version` +} + +fn main() { + cfg_usage(); + + // `cfg(version = "..")` is not a valid `cfg_version` form, but it only triggers + // `unexpected_cfgs` lint, and `cfg(version = "..")` eval to `false`. + key_value_form(); //~ ERROR cannot find function + + // Invalid version literal formats within valid `cfg(version(..))` form should also cause + // `cfg(version(..))` eval to `false`. + not_numbers_or_periods(); //~ ERROR cannot find function + complex_semver_with_metadata(); //~ ERROR cannot find function + invalid_major_only(); //~ ERROR cannot find function + invalid_major_only_zero(); //~ ERROR cannot find function + invalid_major_only_negative(); //~ ERROR cannot find function + exceed_u16_major(); //~ ERROR cannot find function + exceed_u16_minor(); //~ ERROR cannot find function + exceed_u16_patch(); //~ ERROR cannot find function + exceed_u16_mixed(); //~ ERROR cannot find function +} diff --git a/tests/ui/cfg/cfg-version/syntax.stderr b/tests/ui/cfg/cfg-version/syntax.stderr new file mode 100644 index 0000000000000..2facd96076317 --- /dev/null +++ b/tests/ui/cfg/cfg-version/syntax.stderr @@ -0,0 +1,188 @@ +error: expected a version literal + --> $DIR/syntax.rs:11:15 + | +LL | #[cfg(version(42))] + | ^^ + +error: expected a version literal + --> $DIR/syntax.rs:15:15 + | +LL | #[cfg(version(1.20))] + | ^^^^ + +error: expected a version literal + --> $DIR/syntax.rs:19:15 + | +LL | #[cfg(version(false))] + | ^^^^^ + +error: expected single version literal + --> $DIR/syntax.rs:23:7 + | +LL | #[cfg(version("1.43", "1.44", "1.45"))] + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ + +warning: unknown version literal format, assuming it refers to a future version + --> $DIR/syntax.rs:51:15 + | +LL | #[cfg(version("foo"))] + | ^^^^^ + +warning: unknown version literal format, assuming it refers to a future version + --> $DIR/syntax.rs:55:15 + | +LL | #[cfg(version("1.20.0-stable"))] + | ^^^^^^^^^^^^^^^ + +warning: unknown version literal format, assuming it refers to a future version + --> $DIR/syntax.rs:78:15 + | +LL | #[cfg(version("1"))] + | ^^^ + +warning: unknown version literal format, assuming it refers to a future version + --> $DIR/syntax.rs:82:15 + | +LL | #[cfg(version("0"))] + | ^^^ + +warning: unknown version literal format, assuming it refers to a future version + --> $DIR/syntax.rs:86:15 + | +LL | #[cfg(version(".7"))] + | ^^^^ + +warning: unknown version literal format, assuming it refers to a future version + --> $DIR/syntax.rs:95:15 + | +LL | #[cfg(version("-1"))] + | ^^^^ + +warning: unknown version literal format, assuming it refers to a future version + --> $DIR/syntax.rs:101:15 + | +LL | #[cfg(version("65536"))] + | ^^^^^^^ + +warning: unknown version literal format, assuming it refers to a future version + --> $DIR/syntax.rs:105:15 + | +LL | #[cfg(version("1.65536.0"))] + | ^^^^^^^^^^^ + +warning: unknown version literal format, assuming it refers to a future version + --> $DIR/syntax.rs:109:15 + | +LL | #[cfg(version("1.0.65536"))] + | ^^^^^^^^^^^ + +warning: unknown version literal format, assuming it refers to a future version + --> $DIR/syntax.rs:113:15 + | +LL | #[cfg(version("65536.0.65536"))] + | ^^^^^^^^^^^^^^^ + +warning: unknown version literal format, assuming it refers to a future version + --> $DIR/syntax.rs:125:26 + | +LL | assert!(cfg!(version("foo"))); + | ^^^^^ + +warning: unknown version literal format, assuming it refers to a future version + --> $DIR/syntax.rs:127:26 + | +LL | assert!(cfg!(version("1.20.0-stable"))); + | ^^^^^^^^^^^^^^^ + +warning: unexpected `cfg` condition name: `version` + --> $DIR/syntax.rs:30:7 + | +LL | #[cfg(version = "1.43")] + | ^^^^^^^^^^^^^^^^ + | + = help: to expect this configuration use `--check-cfg=cfg(version, values("1.43"))` + = note: see for more information about checking conditional configuration + = note: `#[warn(unexpected_cfgs)]` on by default +help: there is a similar config predicate: `version("..")` + | +LL - #[cfg(version = "1.43")] +LL + #[cfg(version("1.43"))] + | + +warning: unexpected `cfg` condition name: `version` + --> $DIR/syntax.rs:130:18 + | +LL | assert!(cfg!(version = "1.43")); + | ^^^^^^^^^^^^^^^^ + | + = help: to expect this configuration use `--check-cfg=cfg(version, values("1.43"))` + = note: see for more information about checking conditional configuration +help: there is a similar config predicate: `version("..")` + | +LL - assert!(cfg!(version = "1.43")); +LL + assert!(cfg!(version("1.43"))); + | + +error[E0425]: cannot find function `key_value_form` in this scope + --> $DIR/syntax.rs:139:5 + | +LL | key_value_form(); + | ^^^^^^^^^^^^^^ not found in this scope + +error[E0425]: cannot find function `not_numbers_or_periods` in this scope + --> $DIR/syntax.rs:143:5 + | +LL | not_numbers_or_periods(); + | ^^^^^^^^^^^^^^^^^^^^^^ not found in this scope + +error[E0425]: cannot find function `complex_semver_with_metadata` in this scope + --> $DIR/syntax.rs:144:5 + | +LL | complex_semver_with_metadata(); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ not found in this scope + +error[E0425]: cannot find function `invalid_major_only` in this scope + --> $DIR/syntax.rs:145:5 + | +LL | invalid_major_only(); + | ^^^^^^^^^^^^^^^^^^ not found in this scope + +error[E0425]: cannot find function `invalid_major_only_zero` in this scope + --> $DIR/syntax.rs:146:5 + | +LL | invalid_major_only_zero(); + | ^^^^^^^^^^^^^^^^^^^^^^^ not found in this scope + +error[E0425]: cannot find function `invalid_major_only_negative` in this scope + --> $DIR/syntax.rs:147:5 + | +LL | invalid_major_only_negative(); + | ^^^^^^^^^^^^^^^^^^^^^^^^^^^ not found in this scope + +error[E0425]: cannot find function `exceed_u16_major` in this scope + --> $DIR/syntax.rs:148:5 + | +LL | exceed_u16_major(); + | ^^^^^^^^^^^^^^^^ not found in this scope + +error[E0425]: cannot find function `exceed_u16_minor` in this scope + --> $DIR/syntax.rs:149:5 + | +LL | exceed_u16_minor(); + | ^^^^^^^^^^^^^^^^ not found in this scope + +error[E0425]: cannot find function `exceed_u16_patch` in this scope + --> $DIR/syntax.rs:150:5 + | +LL | exceed_u16_patch(); + | ^^^^^^^^^^^^^^^^ not found in this scope + +error[E0425]: cannot find function `exceed_u16_mixed` in this scope + --> $DIR/syntax.rs:151:5 + | +LL | exceed_u16_mixed(); + | ^^^^^^^^^^^^^^^^ not found in this scope + +error: aborting due to 14 previous errors; 14 warnings emitted + +For more information about this error, try `rustc --explain E0425`. diff --git a/tests/ui/feature-gates/feature-gate-cfg-version.rs b/tests/ui/feature-gates/feature-gate-cfg-version.rs index e35784a68d101..ec2446cc14648 100644 --- a/tests/ui/feature-gates/feature-gate-cfg-version.rs +++ b/tests/ui/feature-gates/feature-gate-cfg-version.rs @@ -1,49 +1,12 @@ -#[cfg(version(42))] //~ ERROR: expected a version literal -//~^ ERROR `cfg(version)` is experimental and subject to change -fn foo() {} -#[cfg(version(1.20))] //~ ERROR: expected a version literal -//~^ ERROR `cfg(version)` is experimental and subject to change -fn foo() -> bool { true } -#[cfg(version("1.44"))] -//~^ ERROR `cfg(version)` is experimental and subject to change -fn foo() -> bool { true } -#[cfg(not(version("1.44")))] -//~^ ERROR `cfg(version)` is experimental and subject to change -fn foo() -> bool { false } +//! Feature gate test for `cfg_version`. +//! +//! Tracking issue: #64796. -#[cfg(version("1.43", "1.44", "1.45"))] //~ ERROR: expected single version literal -//~^ ERROR `cfg(version)` is experimental and subject to change -fn bar() -> bool { false } -#[cfg(version(false))] //~ ERROR: expected a version literal -//~^ ERROR `cfg(version)` is experimental and subject to change -fn bar() -> bool { false } -#[cfg(version("foo"))] //~ WARNING: unknown version literal format -//~^ ERROR `cfg(version)` is experimental and subject to change -fn bar() -> bool { false } -#[cfg(version("999"))] //~ WARNING: unknown version literal format -//~^ ERROR `cfg(version)` is experimental and subject to change -fn bar() -> bool { false } -#[cfg(version("-1"))] //~ WARNING: unknown version literal format -//~^ ERROR `cfg(version)` is experimental and subject to change -fn bar() -> bool { false } -#[cfg(version("65536"))] //~ WARNING: unknown version literal format -//~^ ERROR `cfg(version)` is experimental and subject to change -fn bar() -> bool { false } -#[cfg(version("0"))] //~ WARNING: unknown version literal format -//~^ ERROR `cfg(version)` is experimental and subject to change -fn bar() -> bool { true } -#[cfg(version("1.0"))] -//~^ ERROR `cfg(version)` is experimental and subject to change -fn bar() -> bool { true } -#[cfg(version("1.65536.2"))] //~ WARNING: unknown version literal format -//~^ ERROR `cfg(version)` is experimental and subject to change -fn bar() -> bool { false } -#[cfg(version("1.20.0-stable"))] //~ WARNING: unknown version literal format +#[cfg(version("1.42"))] //~^ ERROR `cfg(version)` is experimental and subject to change fn bar() {} fn main() { - assert!(foo()); - assert!(bar()); - assert!(cfg!(version("1.42"))); //~ ERROR `cfg(version)` is experimental and subject to change + assert!(cfg!(version("1.42"))); + //~^ ERROR `cfg(version)` is experimental and subject to change } diff --git a/tests/ui/feature-gates/feature-gate-cfg-version.stderr b/tests/ui/feature-gates/feature-gate-cfg-version.stderr index c1c3e8e5897a6..7cb2f1e07afe6 100644 --- a/tests/ui/feature-gates/feature-gate-cfg-version.stderr +++ b/tests/ui/feature-gates/feature-gate-cfg-version.stderr @@ -1,39 +1,7 @@ error[E0658]: `cfg(version)` is experimental and subject to change - --> $DIR/feature-gate-cfg-version.rs:1:7 + --> $DIR/feature-gate-cfg-version.rs:5:7 | -LL | #[cfg(version(42))] - | ^^^^^^^^^^^ - | - = note: see issue #64796 for more information - = help: add `#![feature(cfg_version)]` to the crate attributes to enable - = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date - -error: expected a version literal - --> $DIR/feature-gate-cfg-version.rs:1:15 - | -LL | #[cfg(version(42))] - | ^^ - -error[E0658]: `cfg(version)` is experimental and subject to change - --> $DIR/feature-gate-cfg-version.rs:4:7 - | -LL | #[cfg(version(1.20))] - | ^^^^^^^^^^^^^ - | - = note: see issue #64796 for more information - = help: add `#![feature(cfg_version)]` to the crate attributes to enable - = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date - -error: expected a version literal - --> $DIR/feature-gate-cfg-version.rs:4:15 - | -LL | #[cfg(version(1.20))] - | ^^^^ - -error[E0658]: `cfg(version)` is experimental and subject to change - --> $DIR/feature-gate-cfg-version.rs:7:7 - | -LL | #[cfg(version("1.44"))] +LL | #[cfg(version("1.42"))] | ^^^^^^^^^^^^^^^ | = note: see issue #64796 for more information @@ -41,171 +9,7 @@ LL | #[cfg(version("1.44"))] = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date error[E0658]: `cfg(version)` is experimental and subject to change - --> $DIR/feature-gate-cfg-version.rs:10:11 - | -LL | #[cfg(not(version("1.44")))] - | ^^^^^^^^^^^^^^^ - | - = note: see issue #64796 for more information - = help: add `#![feature(cfg_version)]` to the crate attributes to enable - = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date - -error[E0658]: `cfg(version)` is experimental and subject to change - --> $DIR/feature-gate-cfg-version.rs:14:7 - | -LL | #[cfg(version("1.43", "1.44", "1.45"))] - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - | - = note: see issue #64796 for more information - = help: add `#![feature(cfg_version)]` to the crate attributes to enable - = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date - -error: expected single version literal - --> $DIR/feature-gate-cfg-version.rs:14:7 - | -LL | #[cfg(version("1.43", "1.44", "1.45"))] - | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ - -error[E0658]: `cfg(version)` is experimental and subject to change - --> $DIR/feature-gate-cfg-version.rs:17:7 - | -LL | #[cfg(version(false))] - | ^^^^^^^^^^^^^^ - | - = note: see issue #64796 for more information - = help: add `#![feature(cfg_version)]` to the crate attributes to enable - = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date - -error: expected a version literal - --> $DIR/feature-gate-cfg-version.rs:17:15 - | -LL | #[cfg(version(false))] - | ^^^^^ - -error[E0658]: `cfg(version)` is experimental and subject to change - --> $DIR/feature-gate-cfg-version.rs:20:7 - | -LL | #[cfg(version("foo"))] - | ^^^^^^^^^^^^^^ - | - = note: see issue #64796 for more information - = help: add `#![feature(cfg_version)]` to the crate attributes to enable - = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date - -warning: unknown version literal format, assuming it refers to a future version - --> $DIR/feature-gate-cfg-version.rs:20:15 - | -LL | #[cfg(version("foo"))] - | ^^^^^ - -error[E0658]: `cfg(version)` is experimental and subject to change - --> $DIR/feature-gate-cfg-version.rs:23:7 - | -LL | #[cfg(version("999"))] - | ^^^^^^^^^^^^^^ - | - = note: see issue #64796 for more information - = help: add `#![feature(cfg_version)]` to the crate attributes to enable - = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date - -warning: unknown version literal format, assuming it refers to a future version - --> $DIR/feature-gate-cfg-version.rs:23:15 - | -LL | #[cfg(version("999"))] - | ^^^^^ - -error[E0658]: `cfg(version)` is experimental and subject to change - --> $DIR/feature-gate-cfg-version.rs:26:7 - | -LL | #[cfg(version("-1"))] - | ^^^^^^^^^^^^^ - | - = note: see issue #64796 for more information - = help: add `#![feature(cfg_version)]` to the crate attributes to enable - = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date - -warning: unknown version literal format, assuming it refers to a future version - --> $DIR/feature-gate-cfg-version.rs:26:15 - | -LL | #[cfg(version("-1"))] - | ^^^^ - -error[E0658]: `cfg(version)` is experimental and subject to change - --> $DIR/feature-gate-cfg-version.rs:29:7 - | -LL | #[cfg(version("65536"))] - | ^^^^^^^^^^^^^^^^ - | - = note: see issue #64796 for more information - = help: add `#![feature(cfg_version)]` to the crate attributes to enable - = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date - -warning: unknown version literal format, assuming it refers to a future version - --> $DIR/feature-gate-cfg-version.rs:29:15 - | -LL | #[cfg(version("65536"))] - | ^^^^^^^ - -error[E0658]: `cfg(version)` is experimental and subject to change - --> $DIR/feature-gate-cfg-version.rs:32:7 - | -LL | #[cfg(version("0"))] - | ^^^^^^^^^^^^ - | - = note: see issue #64796 for more information - = help: add `#![feature(cfg_version)]` to the crate attributes to enable - = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date - -warning: unknown version literal format, assuming it refers to a future version - --> $DIR/feature-gate-cfg-version.rs:32:15 - | -LL | #[cfg(version("0"))] - | ^^^ - -error[E0658]: `cfg(version)` is experimental and subject to change - --> $DIR/feature-gate-cfg-version.rs:35:7 - | -LL | #[cfg(version("1.0"))] - | ^^^^^^^^^^^^^^ - | - = note: see issue #64796 for more information - = help: add `#![feature(cfg_version)]` to the crate attributes to enable - = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date - -error[E0658]: `cfg(version)` is experimental and subject to change - --> $DIR/feature-gate-cfg-version.rs:38:7 - | -LL | #[cfg(version("1.65536.2"))] - | ^^^^^^^^^^^^^^^^^^^^ - | - = note: see issue #64796 for more information - = help: add `#![feature(cfg_version)]` to the crate attributes to enable - = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date - -warning: unknown version literal format, assuming it refers to a future version - --> $DIR/feature-gate-cfg-version.rs:38:15 - | -LL | #[cfg(version("1.65536.2"))] - | ^^^^^^^^^^^ - -error[E0658]: `cfg(version)` is experimental and subject to change - --> $DIR/feature-gate-cfg-version.rs:41:7 - | -LL | #[cfg(version("1.20.0-stable"))] - | ^^^^^^^^^^^^^^^^^^^^^^^^ - | - = note: see issue #64796 for more information - = help: add `#![feature(cfg_version)]` to the crate attributes to enable - = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date - -warning: unknown version literal format, assuming it refers to a future version - --> $DIR/feature-gate-cfg-version.rs:41:15 - | -LL | #[cfg(version("1.20.0-stable"))] - | ^^^^^^^^^^^^^^^ - -error[E0658]: `cfg(version)` is experimental and subject to change - --> $DIR/feature-gate-cfg-version.rs:48:18 + --> $DIR/feature-gate-cfg-version.rs:10:18 | LL | assert!(cfg!(version("1.42"))); | ^^^^^^^^^^^^^^^ @@ -214,6 +18,6 @@ LL | assert!(cfg!(version("1.42"))); = help: add `#![feature(cfg_version)]` to the crate attributes to enable = note: this compiler was built on YYYY-MM-DD; consider upgrading it if it is out of date -error: aborting due to 19 previous errors; 7 warnings emitted +error: aborting due to 2 previous errors For more information about this error, try `rustc --explain E0658`.