diff --git a/debuggers/common/CMakeLists.txt b/debuggers/common/CMakeLists.txt
--- a/debuggers/common/CMakeLists.txt
+++ b/debuggers/common/CMakeLists.txt
@@ -33,6 +33,15 @@
     dialogs/selectcoredialog.ui
 )
 
+# Use old behavior (ignore the visibility properties for static libraries, object
+# libraries, and executables without exports) on target kdevdebuggercommon (so the
+# default public visibility is used).
+# kdevdebuggercommon is used by target test_gdb which is added by ecm_add_test,
+# which doesn't set CMP0063 so old behavior is used.
+# If kdevdebuggercommon honors visibility properties (set to hidden), it will cause
+# linker warnings about direct access to global weak symbol when link against test_gdb
+cmake_policy(SET CMP0063 OLD)
+
 add_library(kdevdebuggercommon STATIC ${debuggercommon_SRCS})
 target_link_libraries(kdevdebuggercommon
     PUBLIC
diff --git a/debuggers/common/midebugger.cpp b/debuggers/common/midebugger.cpp
--- a/debuggers/common/midebugger.cpp
+++ b/debuggers/common/midebugger.cpp
@@ -26,15 +26,15 @@
 #include "debuglog.h"
 #include "mi/micommand.h"
 
-#include "sys/signal.h"
-
 #include <KLocalizedString>
 #include <KMessageBox>
 
 #include <QApplication>
 #include <QString>
 #include <QStringList>
 
+#include <signal.h>
+
 #include <memory>
 
 // #define DEBUG_NO_TRY //to get a backtrace to where the exception was thrown