I have a Mac (OSX 10.7.5) and an Arduino Uno. Everything looks okay in my eyes but can't get it work.
When I try to compile any basic example program I get error like this:
/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/../lib/gcc/avr/4.9.2/../../../../avr/bin/ld: /Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/../libexec/gcc/avr/4.9.2/liblto_plugin.so: error loading plugin: dlopen(/Applications/Arduino.app/Contents/Java/hardware/tools/avr/bin/../libexec/gcc/avr/4.9.2/liblto_plugin.so, 2): Symbol not found: _environ
Expected in: /usr/lib/libSystem.B.dylib* collect2: error: ld returned 1 exit status exit status 1 Error compiling for board Arduino/Genuino Uno.
Any idea what to do? I have already reinstalled and some other basic stuff.
All ideas what to test or do next are welcome. Thank you in advance for all hints.
This issue has been reported here regularly here since the release of Arduino AVR Boards 1.6.12 (bundled with Arduino IDE 1.6.10). It is caused by an LTO (link time optimization) plugin added in that version. I don't believe the cause has ever been found. I can only offer some workarounds:
Option 1: Follow these instructions to revert to the pre-LTO Arduino AVR Boards package:
Tools > Board > Boards Manager
Wait for downloads to finish
Click on "Arduino AVR Boards"
Select 1.6.11 from the "select version" drop down menu.