Hotfix to allow Ctrl+C in python scipts (#3285)

* Ignore _skbuild dirs

* Fixed `Context::use_default_signal_handler(bool)` not having any effect

* formatting

.gitignore

@@ -88,3 +88,4 @@ __cache__/
 installed.json
 tmp/
 test_7.json.state
+_skbuild/

libmamba/include/mamba/core/thread_utils.hpp

@@ -31,6 +31,7 @@ namespace mamba
 #endif
 
     void set_default_signal_handler();
+    void restore_system_signal_handler();
     bool is_sig_interrupted() noexcept;
     void set_sig_interrupted() noexcept;
 

libmamba/src/core/context.cpp

@@ -76,6 +76,14 @@ namespace mamba
     void Context::use_default_signal_handler(bool val)
     {
         use_default_signal_handler_val = val;
+        if (use_default_signal_handler_val)
+        {
+            set_default_signal_handler();
+        }
+        else
+        {
+            restore_system_signal_handler();
+        }
     }
 
     void Context::enable_logging_and_signal_handling(Context& context)

libmamba/src/core/thread_utils.cpp

@@ -95,6 +95,10 @@ namespace mamba
         std::signal(SIGINT, [](int /*signum*/) { set_sig_interrupted(); });
     }
 #endif
+    void restore_system_signal_handler()
+    {
+        std::signal(SIGINT, SIG_DFL);
+    }
 
     bool is_sig_interrupted() noexcept
     {