remove cmake run-rust-unit-tests custom target

diff --git a/AGENTS.md b/AGENTS.md
index a355001..bfec916 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -51,13 +51,16 @@ an explicit shell as the command, e.g. `./scripts/dev_exec.sh bash -lc 'cat vers
      `cargo test --manifest-path src/rust/Cargo.toml [ -p <crate> ] --all-features -- --test-threads 1`.
   -  For checks, use
      `cargo check --manifest-path src/rust/Cargo.toml [ -p <crate> ] --all-features`.
+  -  If you modify `messages/*.proto`, run `make generate-protobufs` before direct Rust `cargo`
+     commands. Plain `cargo test`/`cargo check` does not regenerate the protobuf outputs.
 
 ## Coding Style & Naming Conventions
 `.clang-format` (Chromium base, 4-space indent, Linux braces) and `.clang-tidy` govern C/C++. Use
 `snake_case` for symbols, `PascalCase` for types, and `ALL_CAPS` for macros. Python utilities follow
 `.pylintrc` rules (100-column limit, explicit imports). Rust crates rely on `rustfmt.toml` and the
 pinned toolchain in `rust-toolchain.toml`; keep module paths aligned with `src/rust` and regenerate
-bindings (`cbindgen`, protobuf) when interfaces change.
+bindings (`cbindgen`, protobuf) when interfaces change. When changing protobuf interfaces, run
+`make generate-protobufs`.
 
 * For C code changes, run `./scripts/dev_exec.sh ./scripts/format` to format the code.
 * For Python changes, run `./scripts/dev_exec.sh ./scripts/format-python` to format the code.
diff --git a/Makefile b/Makefile
index 9dfd75c..aff4f81 100644
--- a/Makefile
+++ b/Makefile
@@ -107,8 +107,13 @@ unit-test: | build-build
 # Must compile C tests before running them
 run-unit-tests: | build-build
 	CTEST_OUTPUT_ON_FAILURE=1 $(MAKE) -C build-build test
-run-rust-unit-tests: | build-build-noasan
-	${MAKE} -C build-build-noasan rust-test
+generate-protobufs: | build-build-noasan
+	$(MAKE) -C build-build-noasan generate-protobufs
+# Only one test thread because of unsafe concurrent access to `SafeData`,
+# `mock_sd()` and `mock_memory()`. Using mutexes instead leads to mutex
+# poisoning and very messy output in case of a unit test failure.
+run-rust-unit-tests: generate-protobufs
+	cargo test --manifest-path src/rust/Cargo.toml --all-features -- --test-threads 1
 run-rust-clippy: | build-build-noasan
 	${MAKE} -C build-build-noasan rust-clippy
 # Must run tests before creating coverage report
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 69c825d..ac99bc6 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -247,31 +247,6 @@ add_custom_target(rust-cbindgen
 # Test rust crates that contain business logic. Avoid testing crates that depend on hardware.
 if(NOT CMAKE_CROSSCOMPILING)
 
-  # Since we build with all features we need to use a separate build directory.
-  # Otherwise we invalidate the result from the normal compilation that uses a
-  # different set of features.
-  add_custom_target(rust-test
-    COMMAND
-      ${CMAKE_COMMAND} -E env
-        CMAKE_SYSROOT=${CMAKE_SYSROOT}
-        CMAKE_CURRENT_BINARY_DIR=${CMAKE_CURRENT_BINARY_DIR}
-        # only one test thread because of unsafe concurrent access to `SafeData`, `mock_sd()` and `mock_memory()`. Using mutexes instead leads to mutex poisoning and very messy output in case of a unit test failure.
-        ${CARGO}
-          test
-          $<$<BOOL:${CMAKE_VERBOSE_MAKEFILE}>:-v>
-          --all-features
-          --manifest-path ${CMAKE_CURRENT_SOURCE_DIR}/rust/Cargo.toml
-          --target-dir ${RUST_BINARY_DIR}/all-features
-          --
-          $<$<BOOL:${CMAKE_VERBOSE_MAKEFILE}>:--no-capture>
-          --test-threads 1
-    WORKING_DIRECTORY
-      ${CMAKE_CURRENT_SOURCE_DIR}/rust
-    DEPENDS
-      ${CMAKE_CURRENT_BINARY_DIR}/rust/rust.h
-    )
-  add_dependencies(rust-test generate-protobufs)
-
   add_custom_target(rust-clippy
     COMMAND
       ${CMAKE_COMMAND} -E env