3 files changed, 19 insertions, 0 deletions
diff --git a/src/rust/Cargo.toml b/src/rust/Cargo.toml
index c3e44d2a79..4bbadbe535 100644
--- a/src/rust/Cargo.toml
+++ b/src/rust/Cargo.toml
@@ -14,3 +14,12 @@ members = [
 debug = true
 panic = "abort"
 
+[features]
+default = []
+# If this feature is enabled, test code which calls Tor C code from Rust will
+# execute with `cargo test`.  Due to numerous linker issues (#25386), this is
+# currently disabled by default.  Crates listed here are those which, in their
+# unittests, doctests, and/or integration tests, call C code.
+test-c-from-rust = [
+    "crypto/test-c-from-rust",
+]
diff --git a/src/rust/crypto/Cargo.toml b/src/rust/crypto/Cargo.toml
index 869e0d6256..d68ac48e28 100644
--- a/src/rust/crypto/Cargo.toml
+++ b/src/rust/crypto/Cargo.toml
@@ -26,3 +26,7 @@ rand = { version = "=0.5.0-pre.2", default-features = false }
 rand_core = { version = "=0.2.0-pre.0", default-features = false }
 
 [features]
+# If this feature is enabled, test code which calls Tor C code from Rust will
+# execute with `cargo test`.  Due to numerous linker issues (#25386), this is
+# currently disabled by default.
+test-c-from-rust = []
diff --git a/src/rust/crypto/digests/sha2.rs b/src/rust/crypto/digests/sha2.rs
index 03e0843dc0..d0246eeb94 100644
--- a/src/rust/crypto/digests/sha2.rs
+++ b/src/rust/crypto/digests/sha2.rs
@@ -165,15 +165,19 @@ impl FixedOutput for Sha512 {
 
 #[cfg(test)]
 mod test {
+    #[cfg(feature = "test-c-from-rust")]
     use digest::Digest;
 
+    #[cfg(feature = "test-c-from-rust")]
     use super::*;
 
+    #[cfg(feature = "test-c-from-rust")]
     #[test]
     fn sha256_default() {
         let _: Sha256 = Sha256::default();
     }
 
+    #[cfg(feature = "test-c-from-rust")]
     #[test]
     fn sha256_digest() {
         let mut h: Sha256 = Sha256::new();
@@ -193,11 +197,13 @@ mod test {
         assert_eq!(result, expected);
     }
 
+    #[cfg(feature = "test-c-from-rust")]
     #[test]
     fn sha512_default() {
         let _: Sha512 = Sha512::default();
     }
 
+    #[cfg(feature = "test-c-from-rust")]
     #[test]
     fn sha512_digest() {
         let mut h: Sha512 = Sha512::new();