diff --git a/library/Cargo.lock b/library/Cargo.lock
index f6c14bc58a044..080bfab7fd564 100644
--- a/library/Cargo.lock
+++ b/library/Cargo.lock
@@ -358,6 +358,10 @@ dependencies = [
  "rustc-std-workspace-core",
 ]
 
+[[package]]
+name = "std_detect_tests"
+version = "0.0.0"
+
 [[package]]
 name = "sysroot"
 version = "0.0.0"
diff --git a/library/Cargo.toml b/library/Cargo.toml
index e30e624094285..2d9d4a959b111 100644
--- a/library/Cargo.toml
+++ b/library/Cargo.toml
@@ -7,6 +7,7 @@ members = [
   "sysroot",
   "coretests",
   "alloctests",
+  "std_detect_tests",
 ]
 
 exclude = [
diff --git a/library/std_detect/src/detect/arch/mod.rs b/library/std_detect/src/detect/arch/mod.rs
index 2be7f091c285e..2e545845f8176 100644
--- a/library/std_detect/src/detect/arch/mod.rs
+++ b/library/std_detect/src/detect/arch/mod.rs
@@ -66,7 +66,7 @@ cfg_select! {
     _ => {
         // Unimplemented architecture:
         #[doc(hidden)]
-        pub(crate) enum Feature {
+        pub enum Feature {
             Null
         }
         #[doc(hidden)]
diff --git a/library/std_detect/src/detect/cache.rs b/library/std_detect/src/detect/cache.rs
index c0c0b7b7f8635..e43b76d1419df 100644
--- a/library/std_detect/src/detect/cache.rs
+++ b/library/std_detect/src/detect/cache.rs
@@ -30,21 +30,21 @@ const CACHE_CAPACITY: u32 = 93;
 // The derived `Default` implementation will initialize the field to zero,
 // which is what we want.
 #[derive(Copy, Clone, Default, PartialEq, Eq)]
-pub(crate) struct Initializer(u128);
+pub struct Initializer(u128);
 
 // NOTE: the `debug_assert!` would catch that we do not add more Features than
 // the one fitting our cache.
 impl Initializer {
     /// Tests the `bit` of the cache.
     #[inline]
-    pub(crate) fn test(self, bit: u32) -> bool {
+    pub fn test(self, bit: u32) -> bool {
         debug_assert!(bit < CACHE_CAPACITY, "too many features, time to increase the cache size!");
         test_bit(self.0, bit)
     }
 
     /// Sets the `bit` of the cache.
     #[inline]
-    pub(crate) fn set(&mut self, bit: u32) {
+    pub fn set(&mut self, bit: u32) {
         debug_assert!(bit < CACHE_CAPACITY, "too many features, time to increase the cache size!");
         let v = self.0;
         self.0 = set_bit(v, bit);
diff --git a/library/std_detect/src/detect/macros.rs b/library/std_detect/src/detect/macros.rs
index 17140e15653d2..7a99be5bd2bc4 100644
--- a/library/std_detect/src/detect/macros.rs
+++ b/library/std_detect/src/detect/macros.rs
@@ -149,7 +149,7 @@ macro_rules! features {
         #[repr(u8)]
         #[unstable(feature = "stdarch_internal", issue = "none")]
         #[cfg($cfg)]
-        pub(crate) enum Feature {
+        pub enum Feature {
             $(
                 $(#[$feature_comment])*
                 $feature,
diff --git a/library/std_detect/src/detect/mod.rs b/library/std_detect/src/detect/mod.rs
index c888dd34d9db5..d41526aacd8cc 100644
--- a/library/std_detect/src/detect/mod.rs
+++ b/library/std_detect/src/detect/mod.rs
@@ -32,6 +32,11 @@ pub(crate) use self::arch::Feature;
 mod bit;
 mod cache;
 
+pub mod __test {
+    pub use super::arch::Feature;
+    pub use super::cache::Initializer;
+}
+
 cfg_select! {
     miri => {
         // When running under miri all target-features that are not enabled at
@@ -53,6 +58,14 @@ cfg_select! {
         mod riscv;
         #[path = "os/linux/mod.rs"]
         mod os;
+        #[unstable(feature = "stdarch_internal", issue = "none")]
+        pub mod __test_os {
+            #[cfg(any(target_arch = "riscv32", target_arch = "riscv64"))]
+            pub use super::riscv::imply_features;
+            #[cfg(target_arch = "aarch64")]
+            pub use super::os::aarch64::AtHwcap;
+            pub use super::os::auxvec::{auxv, auxv_from_file};
+        }
     }
     target_os = "freebsd" => {
         #[cfg(target_arch = "aarch64")]
diff --git a/library/std_detect/src/detect/os/linux/aarch64.rs b/library/std_detect/src/detect/os/linux/aarch64.rs
index b733b8a9eb236..b3f6fbb273d20 100644
--- a/library/std_detect/src/detect/os/linux/aarch64.rs
+++ b/library/std_detect/src/detect/os/linux/aarch64.rs
@@ -35,106 +35,106 @@ pub(crate) fn detect_features() -> cache::Initializer {
 ///
 /// [hwcap]: https://github.com/torvalds/linux/blob/master/arch/arm64/include/uapi/asm/hwcap.h
 #[derive(Debug, Default, PartialEq)]
-struct AtHwcap {
+pub struct AtHwcap {
     // AT_HWCAP
-    fp: bool,
-    asimd: bool,
-    // evtstrm: No LLVM support.
-    aes: bool,
-    pmull: bool,
-    sha1: bool,
-    sha2: bool,
-    crc32: bool,
-    atomics: bool,
-    fphp: bool,
-    asimdhp: bool,
-    // cpuid: No LLVM support.
-    asimdrdm: bool,
-    jscvt: bool,
-    fcma: bool,
-    lrcpc: bool,
-    dcpop: bool,
-    sha3: bool,
-    sm3: bool,
-    sm4: bool,
-    asimddp: bool,
-    sha512: bool,
-    sve: bool,
-    fhm: bool,
-    dit: bool,
-    uscat: bool,
-    ilrcpc: bool,
-    flagm: bool,
-    ssbs: bool,
-    sb: bool,
-    paca: bool,
-    pacg: bool,
+    pub fp: bool,
+    pub asimd: bool,
+    // pub evtstrm: No LLVM support.
+    pub aes: bool,
+    pub pmull: bool,
+    pub sha1: bool,
+    pub sha2: bool,
+    pub crc32: bool,
+    pub atomics: bool,
+    pub fphp: bool,
+    pub asimdhp: bool,
+    // pub cpuid: No LLVM support.
+    pub asimdrdm: bool,
+    pub jscvt: bool,
+    pub fcma: bool,
+    pub lrcpc: bool,
+    pub dcpop: bool,
+    pub sha3: bool,
+    pub sm3: bool,
+    pub sm4: bool,
+    pub asimddp: bool,
+    pub sha512: bool,
+    pub sve: bool,
+    pub fhm: bool,
+    pub dit: bool,
+    pub uscat: bool,
+    pub ilrcpc: bool,
+    pub flagm: bool,
+    pub ssbs: bool,
+    pub sb: bool,
+    pub paca: bool,
+    pub pacg: bool,
 
     // AT_HWCAP2
-    dcpodp: bool,
-    sve2: bool,
-    sveaes: bool,
-    svepmull: bool,
-    svebitperm: bool,
-    svesha3: bool,
-    svesm4: bool,
-    flagm2: bool,
-    frint: bool,
-    // svei8mm: See i8mm feature.
-    svef32mm: bool,
-    svef64mm: bool,
-    // svebf16: See bf16 feature.
-    i8mm: bool,
-    bf16: bool,
-    // dgh: No LLVM support.
-    rng: bool,
-    bti: bool,
-    mte: bool,
-    ecv: bool,
-    // afp: bool,
-    // rpres: bool,
-    // mte3: bool,
-    sme: bool,
-    smei16i64: bool,
-    smef64f64: bool,
-    // smei8i32: bool,
-    // smef16f32: bool,
-    // smeb16f32: bool,
-    // smef32f32: bool,
-    smefa64: bool,
-    wfxt: bool,
-    // ebf16: bool,
-    // sveebf16: bool,
-    cssc: bool,
-    // rprfm: bool,
-    sve2p1: bool,
-    sme2: bool,
-    sme2p1: bool,
-    // smei16i32: bool,
-    // smebi32i32: bool,
-    smeb16b16: bool,
-    smef16f16: bool,
-    mops: bool,
-    hbc: bool,
-    sveb16b16: bool,
-    lrcpc3: bool,
-    lse128: bool,
-    fpmr: bool,
-    lut: bool,
-    faminmax: bool,
-    f8cvt: bool,
-    f8fma: bool,
-    f8dp4: bool,
-    f8dp2: bool,
-    f8e4m3: bool,
-    f8e5m2: bool,
-    smelutv2: bool,
-    smef8f16: bool,
-    smef8f32: bool,
-    smesf8fma: bool,
-    smesf8dp4: bool,
-    smesf8dp2: bool,
-    // pauthlr: bool,
+    pub dcpodp: bool,
+    pub sve2: bool,
+    pub sveaes: bool,
+    pub svepmull: bool,
+    pub svebitperm: bool,
+    pub svesha3: bool,
+    pub svesm4: bool,
+    pub flagm2: bool,
+    pub frint: bool,
+    // pub svei8mm: See i8mm feature.
+    pub svef32mm: bool,
+    pub svef64mm: bool,
+    // pub svebf16: See bf16 feature.
+    pub i8mm: bool,
+    pub bf16: bool,
+    // pub dgh: No LLVM support.
+    pub rng: bool,
+    pub bti: bool,
+    pub mte: bool,
+    pub ecv: bool,
+    // pub afp: bool,
+    // pub rpres: bool,
+    // pub mte3: bool,
+    pub sme: bool,
+    pub smei16i64: bool,
+    pub smef64f64: bool,
+    // pub smei8i32: bool,
+    // pub smef16f32: bool,
+    // pub smeb16f32: bool,
+    // pub smef32f32: bool,
+    pub smefa64: bool,
+    pub wfxt: bool,
+    // pub ebf16: bool,
+    // pub sveebf16: bool,
+    pub cssc: bool,
+    // pub rprfm: bool,
+    pub sve2p1: bool,
+    pub sme2: bool,
+    pub sme2p1: bool,
+    // pub smei16i32: bool,
+    // pub smebi32i32: bool,
+    pub smeb16b16: bool,
+    pub smef16f16: bool,
+    pub mops: bool,
+    pub hbc: bool,
+    pub sveb16b16: bool,
+    pub lrcpc3: bool,
+    pub lse128: bool,
+    pub fpmr: bool,
+    pub lut: bool,
+    pub faminmax: bool,
+    pub f8cvt: bool,
+    pub f8fma: bool,
+    pub f8dp4: bool,
+    pub f8dp2: bool,
+    pub f8e4m3: bool,
+    pub f8e5m2: bool,
+    pub smelutv2: bool,
+    pub smef8f16: bool,
+    pub smef8f32: bool,
+    pub smesf8fma: bool,
+    pub smesf8dp4: bool,
+    pub smesf8dp2: bool,
+    // pub pauthlr: bool,
 }
 
 impl From<auxvec::AuxVec> for AtHwcap {
@@ -403,7 +403,3 @@ impl AtHwcap {
         value
     }
 }
-
-#[cfg(target_endian = "little")]
-#[cfg(test)]
-mod tests;
diff --git a/library/std_detect/src/detect/os/linux/auxvec.rs b/library/std_detect/src/detect/os/linux/auxvec.rs
index c0bbc7d4efa88..2a5d475b5f403 100644
--- a/library/std_detect/src/detect/os/linux/auxvec.rs
+++ b/library/std_detect/src/detect/os/linux/auxvec.rs
@@ -20,8 +20,8 @@ pub(crate) const AT_HWCAP2: usize = 26;
 /// If an entry cannot be read all the bits in the bitfield are set to zero.
 /// This should be interpreted as all the features being disabled.
 #[derive(Debug, Copy, Clone)]
-#[cfg_attr(test, derive(PartialEq))]
-pub(crate) struct AuxVec {
+#[derive(PartialEq)]
+pub struct AuxVec {
     pub hwcap: usize,
     #[cfg(any(
         target_arch = "aarch64",
@@ -68,7 +68,7 @@ pub(crate) struct AuxVec {
 /// [auxvec_h]: https://github.com/torvalds/linux/blob/master/include/uapi/linux/auxvec.h
 /// [auxv_docs]: https://docs.rs/auxv/0.3.3/auxv/
 /// [`getauxval`]: https://man7.org/linux/man-pages/man3/getauxval.3.html
-pub(crate) fn auxv() -> Result<AuxVec, ()> {
+pub fn auxv() -> Result<AuxVec, ()> {
     // Try to call a getauxval function.
     if let Ok(hwcap) = getauxval(AT_HWCAP) {
         // Targets with only AT_HWCAP:
@@ -146,13 +146,9 @@ fn getauxval(key: usize) -> Result<usize, ()> {
 
 /// Tries to read the auxiliary vector from the `file`. If this fails, this
 /// function returns `Err`.
-pub(super) fn auxv_from_file(file: &str) -> Result<AuxVec, alloc::string::String> {
-    let file = super::read_file(file)?;
-    auxv_from_file_bytes(&file)
-}
+pub fn auxv_from_file(file: &str) -> Result<AuxVec, alloc::string::String> {
+    let bytes = super::read_file(file)?;
 
-/// Read auxiliary vector from a slice of bytes.
-pub(super) fn auxv_from_file_bytes(bytes: &[u8]) -> Result<AuxVec, alloc::string::String> {
     // See <https://github.com/torvalds/linux/blob/v5.15/include/uapi/linux/auxvec.h>.
     //
     // The auxiliary vector contains at most 34 (key,value) fields: from
@@ -216,6 +212,3 @@ fn auxv_from_buf(buf: &[usize]) -> Result<AuxVec, alloc::string::String> {
     let _ = buf;
     Err(alloc::string::String::from("hwcap not found"))
 }
-
-#[cfg(test)]
-mod tests;
diff --git a/library/std_detect/src/detect/os/linux/mod.rs b/library/std_detect/src/detect/os/linux/mod.rs
index aec94f963f5c1..fe810597bc745 100644
--- a/library/std_detect/src/detect/os/linux/mod.rs
+++ b/library/std_detect/src/detect/os/linux/mod.rs
@@ -2,7 +2,7 @@
 
 use alloc::vec::Vec;
 
-mod auxvec;
+pub(super) mod auxvec;
 
 fn read_file(orig_path: &str) -> Result<Vec<u8>, alloc::string::String> {
     use alloc::format;
@@ -37,7 +37,7 @@ fn read_file(orig_path: &str) -> Result<Vec<u8>, alloc::string::String> {
 
 cfg_select! {
     target_arch = "aarch64" => {
-        mod aarch64;
+        pub(super) mod aarch64;
         pub(crate) use self::aarch64::detect_features;
     }
     target_arch = "arm" => {
diff --git a/library/std_detect/src/detect/os/riscv.rs b/library/std_detect/src/detect/os/riscv.rs
index 9b9e0cba09d1c..1c59cb50e02c9 100644
--- a/library/std_detect/src/detect/os/riscv.rs
+++ b/library/std_detect/src/detect/os/riscv.rs
@@ -18,7 +18,7 @@ use crate::detect::{Feature, cache};
 /// conflicting extensions and/or complicated requirements.  Eliminating such
 /// inconsistencies is the responsibility of the feature detection logic and
 /// its provider(s).
-pub(crate) fn imply_features(mut value: cache::Initializer) -> cache::Initializer {
+pub fn imply_features(mut value: cache::Initializer) -> cache::Initializer {
     loop {
         // Check convergence of the feature flags later.
         let prev = value;
@@ -153,7 +153,3 @@ pub(crate) fn imply_features(mut value: cache::Initializer) -> cache::Initialize
         }
     }
 }
-
-#[cfg(test)]
-#[path = "riscv/tests.rs"]
-mod tests;
diff --git a/library/std_detect_tests/Cargo.toml b/library/std_detect_tests/Cargo.toml
new file mode 100644
index 0000000000000..c908720e6125b
--- /dev/null
+++ b/library/std_detect_tests/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "std_detect_tests"
+version = "0.0.0"
+license = "MIT OR Apache-2.0"
+description = "Tests for std_detect"
+edition = "2024"
diff --git a/library/std_detect/src/detect/test_data/linux-artificial-aarch64.auxv b/library/std_detect_tests/test_data/linux-artificial-aarch64.auxv
similarity index 100%
rename from library/std_detect/src/detect/test_data/linux-artificial-aarch64.auxv
rename to library/std_detect_tests/test_data/linux-artificial-aarch64.auxv
diff --git a/library/std_detect/src/detect/test_data/linux-empty-hwcap2-aarch64.auxv b/library/std_detect_tests/test_data/linux-empty-hwcap2-aarch64.auxv
similarity index 100%
rename from library/std_detect/src/detect/test_data/linux-empty-hwcap2-aarch64.auxv
rename to library/std_detect_tests/test_data/linux-empty-hwcap2-aarch64.auxv
diff --git a/library/std_detect/src/detect/test_data/linux-hwcap2-aarch64.auxv b/library/std_detect_tests/test_data/linux-hwcap2-aarch64.auxv
similarity index 100%
rename from library/std_detect/src/detect/test_data/linux-hwcap2-aarch64.auxv
rename to library/std_detect_tests/test_data/linux-hwcap2-aarch64.auxv
diff --git a/library/std_detect/src/detect/test_data/linux-no-hwcap2-aarch64.auxv b/library/std_detect_tests/test_data/linux-no-hwcap2-aarch64.auxv
similarity index 100%
rename from library/std_detect/src/detect/test_data/linux-no-hwcap2-aarch64.auxv
rename to library/std_detect_tests/test_data/linux-no-hwcap2-aarch64.auxv
diff --git a/library/std_detect/src/detect/test_data/linux-rpi3.auxv b/library/std_detect_tests/test_data/linux-rpi3.auxv
similarity index 100%
rename from library/std_detect/src/detect/test_data/linux-rpi3.auxv
rename to library/std_detect_tests/test_data/linux-rpi3.auxv
diff --git a/library/std_detect/src/detect/test_data/macos-virtualbox-linux-x86-4850HQ.auxv b/library/std_detect_tests/test_data/macos-virtualbox-linux-x86-4850HQ.auxv
similarity index 100%
rename from library/std_detect/src/detect/test_data/macos-virtualbox-linux-x86-4850HQ.auxv
rename to library/std_detect_tests/test_data/macos-virtualbox-linux-x86-4850HQ.auxv
diff --git a/library/std_detect/src/detect/os/linux/auxvec/tests.rs b/library/std_detect_tests/tests/auxvec.rs
similarity index 77%
rename from library/std_detect/src/detect/os/linux/auxvec/tests.rs
rename to library/std_detect_tests/tests/auxvec.rs
index 88f0d6d493376..4b7de8c06480b 100644
--- a/library/std_detect/src/detect/os/linux/auxvec/tests.rs
+++ b/library/std_detect_tests/tests/auxvec.rs
@@ -1,4 +1,9 @@
-use super::*;
+#![allow(internal_features)]
+#![feature(cfg_select, stdarch_internal)]
+
+extern crate std_detect;
+
+use std_detect::detect::__test_os::{auxv, auxv_from_file};
 
 // FIXME: on mips/mips64 getauxval returns 0, and /proc/self/auxv
 // does not always contain the AT_HWCAP key under qemu.
@@ -47,17 +52,17 @@ cfg_select! {
         // files on disk, so we need to embed them with `include_bytes!`.
         #[test]
         fn linux_rpi3() {
-            let auxv = include_bytes!(concat!(env!("CARGO_MANIFEST_DIR"), "/src/detect/test_data/linux-rpi3.auxv"));
-            let v = auxv_from_file_bytes(auxv).unwrap();
+            let file = concat!(env!("CARGO_MANIFEST_DIR"), "/test_data/linux-rpi3.auxv");
+            let v = auxv_from_file(file).unwrap();
             assert_eq!(v.hwcap, 4174038);
             assert_eq!(v.hwcap2, 16);
         }
 
         #[test]
         fn linux_macos_vb() {
-            let auxv = include_bytes!(concat!(env!("CARGO_MANIFEST_DIR"), "/src/detect/test_data/macos-virtualbox-linux-x86-4850HQ.auxv"));
+            let file = concat!(env!("CARGO_MANIFEST_DIR"), "/test_data/macos-virtualbox-linux-x86-4850HQ.auxv");
             // The file contains HWCAP but not HWCAP2. In that case, we treat HWCAP2 as zero.
-            let v = auxv_from_file_bytes(auxv).unwrap();
+            let v = auxv_from_file(file).unwrap();
             assert_eq!(v.hwcap, 126614527);
             assert_eq!(v.hwcap2, 0);
         }
@@ -66,16 +71,16 @@ cfg_select! {
         #[cfg(target_endian = "little")]
         #[test]
         fn linux_artificial_aarch64() {
-            let auxv = include_bytes!(concat!(env!("CARGO_MANIFEST_DIR"), "/src/detect/test_data/linux-artificial-aarch64.auxv"));
-            let v = auxv_from_file_bytes(auxv).unwrap();
+            let file = concat!(env!("CARGO_MANIFEST_DIR"), "/test_data/linux-artificial-aarch64.auxv");
+            let v = auxv_from_file(file).unwrap();
             assert_eq!(v.hwcap, 0x0123456789abcdef);
             assert_eq!(v.hwcap2, 0x02468ace13579bdf);
         }
         #[cfg(target_endian = "little")]
         #[test]
         fn linux_no_hwcap2_aarch64() {
-            let auxv = include_bytes!(concat!(env!("CARGO_MANIFEST_DIR"), "/src/detect/test_data/linux-no-hwcap2-aarch64.auxv"));
-            let v = auxv_from_file_bytes(auxv).unwrap();
+            let file = concat!(env!("CARGO_MANIFEST_DIR"), "/test_data/linux-no-hwcap2-aarch64.auxv");
+            let v = auxv_from_file(file).unwrap();
             // An absent HWCAP2 is treated as zero, and does not prevent acceptance of HWCAP.
             assert_ne!(v.hwcap, 0);
             assert_eq!(v.hwcap2, 0);
diff --git a/library/std_detect/tests/cpu-detection.rs b/library/std_detect_tests/tests/cpu-detection.rs
similarity index 100%
rename from library/std_detect/tests/cpu-detection.rs
rename to library/std_detect_tests/tests/cpu-detection.rs
diff --git a/library/std_detect/src/detect/os/linux/aarch64/tests.rs b/library/std_detect_tests/tests/linux_aarch64.rs
similarity index 73%
rename from library/std_detect/src/detect/os/linux/aarch64/tests.rs
rename to library/std_detect_tests/tests/linux_aarch64.rs
index 4d7c9a419d386..3062f73b389ff 100644
--- a/library/std_detect/src/detect/os/linux/aarch64/tests.rs
+++ b/library/std_detect_tests/tests/linux_aarch64.rs
@@ -1,5 +1,15 @@
-use super::auxvec::auxv_from_file;
-use super::*;
+#![cfg(all(
+    any(target_os = "linux", target_os = "android"),
+    target_arch = "aarch64",
+    target_endian = "little"
+))]
+#![allow(internal_features)]
+#![feature(stdarch_internal)]
+
+extern crate std_detect;
+
+use std_detect::detect::__test_os::{AtHwcap, auxv_from_file};
+
 // The baseline hwcaps used in the (artificial) auxv test files.
 fn baseline_hwcaps() -> AtHwcap {
     AtHwcap {
@@ -24,10 +34,7 @@ fn baseline_hwcaps() -> AtHwcap {
 
 #[test]
 fn linux_empty_hwcap2_aarch64() {
-    let file = concat!(
-        env!("CARGO_MANIFEST_DIR"),
-        "/src/detect/test_data/linux-empty-hwcap2-aarch64.auxv"
-    );
+    let file = concat!(env!("CARGO_MANIFEST_DIR"), "/test_data/linux-empty-hwcap2-aarch64.auxv");
     println!("file: {file}");
     let v = auxv_from_file(file).unwrap();
     println!("HWCAP : 0x{:0x}", v.hwcap);
@@ -36,8 +43,7 @@ fn linux_empty_hwcap2_aarch64() {
 }
 #[test]
 fn linux_no_hwcap2_aarch64() {
-    let file =
-        concat!(env!("CARGO_MANIFEST_DIR"), "/src/detect/test_data/linux-no-hwcap2-aarch64.auxv");
+    let file = concat!(env!("CARGO_MANIFEST_DIR"), "/test_data/linux-no-hwcap2-aarch64.auxv");
     println!("file: {file}");
     let v = auxv_from_file(file).unwrap();
     println!("HWCAP : 0x{:0x}", v.hwcap);
@@ -46,8 +52,7 @@ fn linux_no_hwcap2_aarch64() {
 }
 #[test]
 fn linux_hwcap2_aarch64() {
-    let file =
-        concat!(env!("CARGO_MANIFEST_DIR"), "/src/detect/test_data/linux-hwcap2-aarch64.auxv");
+    let file = concat!(env!("CARGO_MANIFEST_DIR"), "/test_data/linux-hwcap2-aarch64.auxv");
     println!("file: {file}");
     let v = auxv_from_file(file).unwrap();
     println!("HWCAP : 0x{:0x}", v.hwcap);
diff --git a/library/std_detect/tests/macro_trailing_commas.rs b/library/std_detect_tests/tests/macro_trailing_commas.rs
similarity index 100%
rename from library/std_detect/tests/macro_trailing_commas.rs
rename to library/std_detect_tests/tests/macro_trailing_commas.rs
diff --git a/library/std_detect/src/detect/os/riscv/tests.rs b/library/std_detect_tests/tests/riscv.rs
similarity index 76%
rename from library/std_detect/src/detect/os/riscv/tests.rs
rename to library/std_detect_tests/tests/riscv.rs
index 99a81dee05a6c..417fb6a35d93c 100644
--- a/library/std_detect/src/detect/os/riscv/tests.rs
+++ b/library/std_detect_tests/tests/riscv.rs
@@ -1,8 +1,15 @@
-use super::*;
+#![cfg(any(target_arch = "riscv32", target_arch = "riscv64"))]
+#![allow(internal_features)]
+#![feature(stdarch_internal)]
+
+extern crate std_detect;
+
+use std_detect::detect::__test::{Feature, Initializer};
+use std_detect::detect::__test_os::imply_features;
 
 #[test]
 fn simple_direct() {
-    let mut value = cache::Initializer::default();
+    let mut value = Initializer::default();
     value.set(Feature::f as u32);
     // F (and other extensions with CSRs) -> Zicsr
     assert!(imply_features(value).test(Feature::zicsr as u32));
@@ -10,7 +17,7 @@ fn simple_direct() {
 
 #[test]
 fn simple_indirect() {
-    let mut value = cache::Initializer::default();
+    let mut value = Initializer::default();
     value.set(Feature::q as u32);
     // Q -> D, D -> F, F -> Zicsr
     assert!(imply_features(value).test(Feature::zicsr as u32));
@@ -18,7 +25,7 @@ fn simple_indirect() {
 
 #[test]
 fn complex_zcd() {
-    let mut value = cache::Initializer::default();
+    let mut value = Initializer::default();
     // C & D -> Zcd
     value.set(Feature::c as u32);
     assert!(!imply_features(value).test(Feature::zcd as u32));
@@ -28,7 +35,7 @@ fn complex_zcd() {
 
 #[test]
 fn group_simple_forward() {
-    let mut value = cache::Initializer::default();
+    let mut value = Initializer::default();
     // A -> Zalrsc & Zaamo (forward implication)
     value.set(Feature::a as u32);
     let value = imply_features(value);
@@ -38,7 +45,7 @@ fn group_simple_forward() {
 
 #[test]
 fn group_simple_backward() {
-    let mut value = cache::Initializer::default();
+    let mut value = Initializer::default();
     // Zalrsc & Zaamo -> A (reverse implication)
     value.set(Feature::zalrsc as u32);
     value.set(Feature::zaamo as u32);
@@ -47,7 +54,7 @@ fn group_simple_backward() {
 
 #[test]
 fn group_complex_convergence() {
-    let mut value = cache::Initializer::default();
+    let mut value = Initializer::default();
     // Needs 3 iterations to converge
     // (and 4th iteration for convergence checking):
     // 1.  [Zvksc] -> Zvks & Zvbc
diff --git a/library/std_detect/tests/x86-specific.rs b/library/std_detect_tests/tests/x86-specific.rs
similarity index 100%
rename from library/std_detect/tests/x86-specific.rs
rename to library/std_detect_tests/tests/x86-specific.rs
diff --git a/src/bootstrap/src/core/build_steps/check.rs b/src/bootstrap/src/core/build_steps/check.rs
index f983c59f9bf8c..73b16a1cbf96c 100644
--- a/src/bootstrap/src/core/build_steps/check.rs
+++ b/src/bootstrap/src/core/build_steps/check.rs
@@ -33,7 +33,7 @@ pub struct Std {
 }
 
 impl Std {
-    const CRATE_OR_DEPS: &[&str] = &["sysroot", "coretests", "alloctests"];
+    const CRATE_OR_DEPS: &[&str] = &["sysroot", "coretests", "alloctests", "std_detect_tests"];
 }
 
 impl Step for Std {
diff --git a/src/bootstrap/src/core/build_steps/test.rs b/src/bootstrap/src/core/build_steps/test.rs
index f3a1c6b0e3dde..1c76e9643b697 100644
--- a/src/bootstrap/src/core/build_steps/test.rs
+++ b/src/bootstrap/src/core/build_steps/test.rs
@@ -3005,7 +3005,10 @@ impl Step for Crate {
     type Output = ();
 
     fn should_run(run: ShouldRun<'_>) -> ShouldRun<'_> {
-        run.crate_or_deps("sysroot").crate_or_deps("coretests").crate_or_deps("alloctests")
+        run.crate_or_deps("sysroot")
+            .crate_or_deps("coretests")
+            .crate_or_deps("alloctests")
+            .crate_or_deps("std_detect_tests")
     }
 
     fn is_default_step(_builder: &Builder<'_>) -> bool {
@@ -3125,6 +3128,9 @@ impl Step for Crate {
         if crates.iter().any(|crate_| crate_ == "alloc") {
             crates.push("alloctests".to_owned());
         }
+        if crates.iter().any(|crate_| crate_ == "std_detect") {
+            crates.push("std_detect_tests".to_owned());
+        }
 
         run_cargo_test(cargo, &[], &crates, &*crate_description(&self.crates), target, builder);
     }
diff --git a/src/bootstrap/src/core/builder/cli_paths/snapshots/x_bench.snap b/src/bootstrap/src/core/builder/cli_paths/snapshots/x_bench.snap
index 8a7815487913e..504f954b29951 100644
--- a/src/bootstrap/src/core/builder/cli_paths/snapshots/x_bench.snap
+++ b/src/bootstrap/src/core/builder/cli_paths/snapshots/x_bench.snap
@@ -15,6 +15,7 @@ expression: bench
     - Set({bench::library/rustc-std-workspace-core})
     - Set({bench::library/std})
     - Set({bench::library/std_detect})
+    - Set({bench::library/std_detect_tests})
     - Set({bench::library/sysroot})
     - Set({bench::library/test})
     - Set({bench::library/unwind})
diff --git a/src/bootstrap/src/core/builder/cli_paths/snapshots/x_check.snap b/src/bootstrap/src/core/builder/cli_paths/snapshots/x_check.snap
index 0fe26fac57fc5..d7bbe88cfb457 100644
--- a/src/bootstrap/src/core/builder/cli_paths/snapshots/x_check.snap
+++ b/src/bootstrap/src/core/builder/cli_paths/snapshots/x_check.snap
@@ -129,6 +129,7 @@ expression: check
     - Set({check::library/rustc-std-workspace-core})
     - Set({check::library/std})
     - Set({check::library/std_detect})
+    - Set({check::library/std_detect_tests})
     - Set({check::library/sysroot})
     - Set({check::library/test})
     - Set({check::library/unwind})
diff --git a/src/bootstrap/src/core/builder/cli_paths/snapshots/x_check_compiletest_include_default_paths.snap b/src/bootstrap/src/core/builder/cli_paths/snapshots/x_check_compiletest_include_default_paths.snap
index dae515c67ec6d..56af0b77bf3c3 100644
--- a/src/bootstrap/src/core/builder/cli_paths/snapshots/x_check_compiletest_include_default_paths.snap
+++ b/src/bootstrap/src/core/builder/cli_paths/snapshots/x_check_compiletest_include_default_paths.snap
@@ -129,6 +129,7 @@ expression: check compiletest --include-default-paths
     - Set({check::library/rustc-std-workspace-core})
     - Set({check::library/std})
     - Set({check::library/std_detect})
+    - Set({check::library/std_detect_tests})
     - Set({check::library/sysroot})
     - Set({check::library/test})
     - Set({check::library/unwind})
diff --git a/src/bootstrap/src/core/builder/cli_paths/snapshots/x_check_library.snap b/src/bootstrap/src/core/builder/cli_paths/snapshots/x_check_library.snap
index 1a41aa98555b6..e1ef04dcf2669 100644
--- a/src/bootstrap/src/core/builder/cli_paths/snapshots/x_check_library.snap
+++ b/src/bootstrap/src/core/builder/cli_paths/snapshots/x_check_library.snap
@@ -16,6 +16,7 @@ expression: check library
     - Set({check::library/rustc-std-workspace-core})
     - Set({check::library/std})
     - Set({check::library/std_detect})
+    - Set({check::library/std_detect_tests})
     - Set({check::library/sysroot})
     - Set({check::library/test})
     - Set({check::library/unwind})
diff --git a/src/bootstrap/src/core/builder/cli_paths/snapshots/x_fix.snap b/src/bootstrap/src/core/builder/cli_paths/snapshots/x_fix.snap
index 222c0ffb40503..d7a8b466fc80e 100644
--- a/src/bootstrap/src/core/builder/cli_paths/snapshots/x_fix.snap
+++ b/src/bootstrap/src/core/builder/cli_paths/snapshots/x_fix.snap
@@ -129,6 +129,7 @@ expression: fix
     - Set({fix::library/rustc-std-workspace-core})
     - Set({fix::library/std})
     - Set({fix::library/std_detect})
+    - Set({fix::library/std_detect_tests})
     - Set({fix::library/sysroot})
     - Set({fix::library/test})
     - Set({fix::library/unwind})
diff --git a/src/bootstrap/src/core/builder/cli_paths/snapshots/x_miri.snap b/src/bootstrap/src/core/builder/cli_paths/snapshots/x_miri.snap
index 552697b378bcc..e61249a6e7f34 100644
--- a/src/bootstrap/src/core/builder/cli_paths/snapshots/x_miri.snap
+++ b/src/bootstrap/src/core/builder/cli_paths/snapshots/x_miri.snap
@@ -15,6 +15,7 @@ expression: miri
     - Set({miri::library/rustc-std-workspace-core})
     - Set({miri::library/std})
     - Set({miri::library/std_detect})
+    - Set({miri::library/std_detect_tests})
     - Set({miri::library/sysroot})
     - Set({miri::library/test})
     - Set({miri::library/unwind})
diff --git a/src/bootstrap/src/core/builder/cli_paths/snapshots/x_test.snap b/src/bootstrap/src/core/builder/cli_paths/snapshots/x_test.snap
index 4ab84c3cabc1a..70271cab48bf5 100644
--- a/src/bootstrap/src/core/builder/cli_paths/snapshots/x_test.snap
+++ b/src/bootstrap/src/core/builder/cli_paths/snapshots/x_test.snap
@@ -65,6 +65,7 @@ expression: test
     - Set({test::library/rustc-std-workspace-core})
     - Set({test::library/std})
     - Set({test::library/std_detect})
+    - Set({test::library/std_detect_tests})
     - Set({test::library/sysroot})
     - Set({test::library/test})
     - Set({test::library/unwind})
diff --git a/src/bootstrap/src/core/builder/cli_paths/snapshots/x_test_library.snap b/src/bootstrap/src/core/builder/cli_paths/snapshots/x_test_library.snap
index dfc397597a877..b74912ce7f460 100644
--- a/src/bootstrap/src/core/builder/cli_paths/snapshots/x_test_library.snap
+++ b/src/bootstrap/src/core/builder/cli_paths/snapshots/x_test_library.snap
@@ -15,6 +15,7 @@ expression: test library
     - Set({test::library/rustc-std-workspace-core})
     - Set({test::library/std})
     - Set({test::library/std_detect})
+    - Set({test::library/std_detect_tests})
     - Set({test::library/sysroot})
     - Set({test::library/test})
     - Set({test::library/unwind})
diff --git a/src/bootstrap/src/core/builder/cli_paths/snapshots/x_test_skip_coverage.snap b/src/bootstrap/src/core/builder/cli_paths/snapshots/x_test_skip_coverage.snap
index 2a4805e4fd687..bba6987da7b06 100644
--- a/src/bootstrap/src/core/builder/cli_paths/snapshots/x_test_skip_coverage.snap
+++ b/src/bootstrap/src/core/builder/cli_paths/snapshots/x_test_skip_coverage.snap
@@ -64,6 +64,7 @@ expression: test --skip=coverage
     - Set({test::library/rustc-std-workspace-core})
     - Set({test::library/std})
     - Set({test::library/std_detect})
+    - Set({test::library/std_detect_tests})
     - Set({test::library/sysroot})
     - Set({test::library/test})
     - Set({test::library/unwind})
diff --git a/src/bootstrap/src/core/builder/cli_paths/snapshots/x_test_skip_tests.snap b/src/bootstrap/src/core/builder/cli_paths/snapshots/x_test_skip_tests.snap
index 1468964c78189..fcd5e0da39ccf 100644
--- a/src/bootstrap/src/core/builder/cli_paths/snapshots/x_test_skip_tests.snap
+++ b/src/bootstrap/src/core/builder/cli_paths/snapshots/x_test_skip_tests.snap
@@ -1,6 +1,5 @@
 ---
 source: src/bootstrap/src/core/builder/cli_paths/tests.rs
-assertion_line: 68
 expression: test --skip=tests
 ---
 [Test] test::Tidy
@@ -29,6 +28,7 @@ expression: test --skip=tests
     - Set({test::library/rustc-std-workspace-core})
     - Set({test::library/std})
     - Set({test::library/std_detect})
+    - Set({test::library/std_detect_tests})
     - Set({test::library/sysroot})
     - Set({test::library/test})
     - Set({test::library/unwind})
diff --git a/src/tools/tidy/src/unit_tests.rs b/src/tools/tidy/src/unit_tests.rs
index 74b6c4a3845a6..7d36797b270e0 100644
--- a/src/tools/tidy/src/unit_tests.rs
+++ b/src/tools/tidy/src/unit_tests.rs
@@ -3,7 +3,7 @@
 //!
 //! `core` and `alloc` cannot be tested directly due to duplicating lang items.
 //! All tests and benchmarks must be written externally in
-//! `{coretests,alloctests}/{tests,benches}`.
+//! `*tests/{tests,benches}`.
 //!
 //! Outside of the standard library, tests and benchmarks should be outlined
 //! into separate files named `tests.rs` or `benches.rs`, or directories named
@@ -52,7 +52,7 @@ pub fn check(root_path: &Path, stdlib: bool, tidy_ctx: TidyCtx) {
 
         if is_dir {
             // FIXME remove those exceptions once no longer necessary
-            file_name == "std_detect" || file_name == "std" || file_name == "test"
+            file_name == "std" || file_name == "test"
         } else {
             // Tests which use non-public internals and, as such, need to
             // have the types in the same crate as the tests themselves. See