diff --git a/CMakeLists.txt b/CMakeLists.txt
index 89b8d4b064e087ba3c653bdbdf0e85e69e5b7d0f..c803bca531d6bb691c9fae4f175850a6cc183216 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -55,7 +55,7 @@ add_executable(caosdbcli src/caosdbcli.cpp)
 
 # linting is active when BUILD_TYPE == "Debug"
 if("${CMAKE_BUILD_TYPE}" MATCHES "Debug")
-  #set(_LINTING ON)
+    set(_LINTING ON)
 endif()
 if(_LINTING)
     find_program(iwyu
diff --git a/cmake/CodeCoverage.cmake b/cmake/CodeCoverage.cmake
index 10d27438caa3960dc202f856f4d02223da10bb74..27c6028d70eb608de54f879d4d6e4b59d070f2aa 100644
--- a/cmake/CodeCoverage.cmake
+++ b/cmake/CodeCoverage.cmake
@@ -82,6 +82,11 @@
 # 2021-05-20, Timm Fitschen <t.fitschen@indiscale.com>
 #     - Fix: this script should also accept GCC as a (plain) C compiler.
 #
+# 2021-07-05, Timm Fitschen <t.fitschen@indiscale.com>
+#     - Removed -fprofile-abs-path again, because it would not work when using
+#       gcc as compiler, but clang-tidy as linter. Probably there is a better fix.
+#       clang error: `error: unknown argument: '-fprofile-abs-path' [clang-diagnostic-error]`
+#
 # USAGE:
 #
 # 1. Copy this file into your cmake modules path.
@@ -165,13 +170,13 @@ endif()
 
 set(COVERAGE_COMPILER_FLAGS "-g -fprofile-arcs -ftest-coverage"
     CACHE INTERNAL "")
-if(CMAKE_CXX_COMPILER_ID MATCHES "(GNU|Clang)")
-    include(CheckCXXCompilerFlag)
-    check_cxx_compiler_flag(-fprofile-abs-path HAVE_fprofile_abs_path)
-    if(HAVE_fprofile_abs_path)
-        set(COVERAGE_COMPILER_FLAGS "${COVERAGE_COMPILER_FLAGS} -fprofile-abs-path")
-    endif()
-endif()
+#if(CMAKE_CXX_COMPILER_ID MATCHES "(GNU|Clang)")
+    #include(CheckCXXCompilerFlag)
+    #check_cxx_compiler_flag(-fprofile-abs-path HAVE_fprofile_abs_path)
+    #if(HAVE_fprofile_abs_path)
+        #set(COVERAGE_COMPILER_FLAGS "${COVERAGE_COMPILER_FLAGS} -fprofile-abs-path")
+    #endif()
+#endif()
 
 set(CMAKE_Fortran_FLAGS_COVERAGE
     ${COVERAGE_COMPILER_FLAGS}
diff --git a/src/caosdb/connection.cpp b/src/caosdb/connection.cpp
index f2a3bfd9bce2f5b4d910cd0fdd91ea7c7dbb1ce6..220513317baa0460785f06215edb6c8843cbfd3f 100644
--- a/src/caosdb/connection.cpp
+++ b/src/caosdb/connection.cpp
@@ -115,7 +115,6 @@ SslCaosDBConnectionConfig::SslCaosDBConnectionConfig(
   : CaosDBConnectionConfig(host, port) {
   SslCredentialsOptions options;
   options.pem_root_certs = cacert->getCACertPem();
-  std::cout << "HERE" << options.pem_root_certs;
   this->credentials = SslCredentials(options);
 }
 
@@ -159,7 +158,7 @@ auto operator<<(std::ostream &out, const CaosDBConnection &connection)
 
 [[nodiscard]] auto CaosDBConnection::getVersionInfo() const
   -> std::unique_ptr<VersionInfo> {
-  GetVersionInfoRequest request;
+  const GetVersionInfoRequest request;
   GetVersionInfoResponse response;
   grpc::ClientContext context;
   const grpc::Status status =
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 80a98f88189a3805175fd4900dbe7b3a43404864..d1e1c4df28c3f0398a26c1d87f5a2be821da2deb 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -77,6 +77,7 @@ if (LCOV_PATH)
         LCOV_ARGS --rc lcov_branch_coverage=1 --no-external
         GENHTML_ARGS --rc lcov_branch_coverage=1
         )
+    message(STATUS "Adding COMPILE_FLAGS for coverage: ${COVERAGE_COMPILER_FLAGS}")
     set_target_properties(caosdb PROPERTIES
         COMPILE_FLAGS "${CMAKE_CXX_FLAGS} ${COVERAGE_COMPILER_FLAGS}")
 else ()
diff --git a/test/test_connection.cpp b/test/test_connection.cpp
index 066067185d6c5bf63cadff8901ac01373a12a298..6ae9f0f2fd8730187d46a7a34ed5b09824419401 100644
--- a/test/test_connection.cpp
+++ b/test/test_connection.cpp
@@ -27,7 +27,7 @@
 #include "gtest/gtest_pred_impl.h" // for Test, AssertionResult, EXPECT_EQ
 namespace grpc {
 class ChannelCredentials;
-}
+} // namespace grpc
 
 namespace caosdb::connection {