Use a Logger to print initialization errors

This way the errors will get written to a file instead of to STDERR if
`YABRIDGE_DEBUG_FILE` is set.

CHANGELOG.md

@@ -12,6 +12,7 @@ Versioning](https://semver.org/spec/v2.0.0.html).
 
 - Changed installation recommendations to only install using symlinks with hosts
   that support individually sandboxed plugins.
+- Respect `YABRIDGE_DEBUG_FILE` when printing initialization errors.
 
 ## [1.1.0] - 2020-05-07
 

README.md

@@ -378,13 +378,13 @@ as the _Windows VST plugin_. The whole process works as follows:
    the `dispatcher()` and `audioMaster()` functions respectively. For operations
    involving the plugin editor there is also some extra glue in
    `WineBridge::dispatch_wrapper`. On the receiving end of the function calls,
-   the `passthrough_event()` function calls the callback functions and handles
+   the `passthrough_event()` function which calls the callback functions and
-   the marshalling between our data types created by the `*DataConverter`
+   handles the marshalling between our data types created by the
-   classes and the VST API's different pointer types. This behaviour is
+   `*DataConverter` classes and the VST API's different pointer types. This
-   separated from `receive_event()` so we can handle MIDI events separately.
+   behaviour is separated from `receive_event()` so we can handle MIDI events
-   This is needed because a select few plugins only store pointers to the
+   separately. This is needed because a select few plugins only store pointers
-   received events rather than copies of the objects. Because of this, the
+   to the received events rather than copies of the objects. Because of this,
-   received event data must live at least until the next audio buffer gets
+   the received event data must live at least until the next audio buffer gets
    processed so it needs to be stored temporarily.
 
 6. The Wine VST host loads the Windows VST plugin and starts forwarding messages

src/plugin/plugin.cpp

@@ -19,6 +19,7 @@
 #include <iostream>
 #include <memory>
 
+#include "../common/logging.h"
 #include "plugin-bridge.h"
 
 #define VST_EXPORT __attribute__((visibility("default")))
@@ -55,8 +56,9 @@ VST_EXPORT AEffect* VSTPluginMain(audioMasterCallback host_callback) {
 
         return &bridge->plugin;
     } catch (const std::exception& error) {
-        std::cerr << "Error during initialization:" << std::endl;
+        Logger logger = Logger::create_from_environment();
-        std::cerr << error.what() << std::endl;
+        logger.log("Error during initialization:");
+        logger.log(error.what());
 
         return nullptr;
     }