diff --git a/pkgs/by-name/be/bear/0001-exclude-tests-from-all.patch b/pkgs/by-name/be/bear/0001-exclude-tests-from-all.patch
deleted file mode 100644
index 4a72bb41bbed..000000000000
--- a/pkgs/by-name/be/bear/0001-exclude-tests-from-all.patch
+++ /dev/null
@@ -1,23 +0,0 @@
---- a/CMakeLists.txt
-+++ b/CMakeLists.txt
-@@ -85,8 +85,9 @@
-             ${CMAKE_CACHE_ARGS_EXTRA}
-         BUILD_ALWAYS
-             1
--        TEST_BEFORE_INSTALL
-+        TEST_EXCLUDE_FROM_MAIN
-             1
-+        STEP_TARGETS test
-         TEST_COMMAND
-             ctest # or `ctest -T memcheck`
-         )
-@@ -102,7 +103,8 @@
-                 -DCMAKE_INSTALL_LIBDIR:PATH=${CMAKE_INSTALL_LIBDIR}
-                 -DCMAKE_INSTALL_BINDIR:PATH=${CMAKE_INSTALL_BINDIR}
-                 -DSTAGED_INSTALL_PREFIX:PATH=${STAGED_INSTALL_PREFIX}
--            TEST_BEFORE_INSTALL
-+            TEST_EXCLUDE_FROM_MAIN
-+            STEP_TARGETS test
-                 1
-             INSTALL_COMMAND
-                 ""
diff --git a/pkgs/by-name/be/bear/package.nix b/pkgs/by-name/be/bear/package.nix
index 5ace2224e728..ea69998aa5c3 100644
--- a/pkgs/by-name/be/bear/package.nix
+++ b/pkgs/by-name/be/bear/package.nix
@@ -1,110 +1,43 @@
 {
   lib,
-  stdenv,
   fetchFromGitHub,
-  cmake,
-  ninja,
-  pkg-config,
-  grpc,
-  protobuf,
-  openssl,
-  nlohmann_json,
-  gtest,
-  spdlog,
-  c-ares,
-  zlib,
-  sqlite,
-  re2,
-  lit,
-  python3,
-  coreutils,
+  rustPlatform,
+  installShellFiles,
+  lld,
 }:
 
-stdenv.mkDerivation (finalAttrs: {
+rustPlatform.buildRustPackage (finalAttrs: {
   pname = "bear";
-  version = "3.1.6";
+  version = "4.0.3";
 
   src = fetchFromGitHub {
     owner = "rizsotto";
     repo = "bear";
     rev = finalAttrs.version;
-    hash = "sha256-fWNMjqF5PCjGfFGReKIUiJ5lv8z6j7HeBn5hvbnV2V4=";
+    hash = "sha256-VZNrWfeeOJ5+qLg6hby4vR5rKKO7+mVOKp2p+lvwGOc=";
   };
 
-  strictDeps = true;
+  cargoHash = "sha256-61hKYDPPQ79QF3BNCLn2LxiCsoll+MGAMZ8obOVuNZI=";
 
   nativeBuildInputs = [
-    cmake
-    ninja
-    pkg-config
-    grpc
-    protobuf
+    installShellFiles
+    lld
   ];
 
-  buildInputs = [
-    grpc
-    protobuf
-    openssl
-    nlohmann_json
-    spdlog
-    c-ares
-    zlib
-    sqlite
-    re2
-  ];
-
-  patches = [
-    # This patch is necessary to run tests in a separate phase. By default
-    # test targets are run with ALL, which is not what we want. This patch creates
-    # separate 'test' step targets for each cmake ExternalProject:
-    # - BearTest-test (functional lit tests)
-    # - BearSource-test (unit tests via gtest)
-    ./0001-exclude-tests-from-all.patch
-  ];
-
-  nativeCheckInputs = [
-    lit
-    python3
-  ];
-
-  checkInputs = [
-    gtest
-  ];
-
-  cmakeFlags = [
-    # Build system and generated files concatenate install prefix and
-    # CMAKE_INSTALL_{BIN,LIB}DIR, which breaks if these are absolute paths.
-    (lib.cmakeFeature "CMAKE_INSTALL_BINDIR" "bin")
-    (lib.cmakeFeature "CMAKE_INSTALL_LIBDIR" "lib")
-    (lib.cmakeBool "ENABLE_UNIT_TESTS" finalAttrs.finalPackage.doCheck)
-    (lib.cmakeBool "ENABLE_FUNC_TESTS" finalAttrs.finalPackage.doCheck)
-  ];
-
-  checkTarget = lib.concatStringsSep " " [
-    "BearTest-test"
-    "BearSource-test"
-  ];
-
-  doCheck = true;
-
-  env = {
-    # Disable failing tests. The cause is not immediately clear.
-    LIT_FILTER_OUT = lib.concatStringsSep "|" [
-      "cases/compilation/output/config/filter_compilers.sh"
-      "cases/intercept/preload/posix/execvpe/success_to_resolve.c"
-      "cases/intercept/preload/posix/popen/success.c"
-      "cases/intercept/preload/posix/posix_spawnp/success_to_resolve.c"
-      "cases/intercept/preload/posix/system/success.c"
-      "cases/intercept/preload/shell_commands_intercepted_without_shebang.sh"
-    ];
-  };
-
   postPatch = ''
-    patchShebangs test/bin
+    substituteInPlace bear/build.rs \
+      --replace-fail 'const DEFAULT_WRAPPER_PATH: &str = "/usr/local/libexec/bear";' \
+        "const DEFAULT_WRAPPER_PATH: &str = \"$out/libexec/bear\";" \
+      --replace-fail 'const DEFAULT_PRELOAD_PATH: &str = "/usr/local/libexec/bear/$LIB";' \
+        "const DEFAULT_PRELOAD_PATH: &str = \"$out/lib\";"
+  '';
 
-    # /usr/bin/env is used in test commands and embedded scripts.
-    find test -name '*.sh' \
-      -exec sed -i -e 's|/usr/bin/env|${coreutils}/bin/env|g' {} +
+  postInstall = ''
+    # wrapper should not end up on path
+    install -d $out/libexec/bear
+    mv $out/bin/wrapper $out/libexec/bear/wrapper
+
+    installManPage man/bear.1
   '';
 
   # Functional tests use loopback networking.