Fix IDE auto-download in OSX Catalina (64-bit only OS)

[jgfoster]

System: macOS

See #149 for details.

Downloading 1.8.6 instead of most recent (currently 1.8.13)

This is a follow-up from the "bad CPU type in executable" problem reported in #149. If a copy of the IDE is not found, we download one. Unfortunately, the (hard-coded?) version obtained (1.8.6) does not work on macOS 10.16 because it is not a 64-bit application.

Workaround

Delete the Arduino.app in the Documents directory and install the current version in the /Applications directory.

[jgfoster]

Another work-around is to edit ./vendor/bundle/ruby/2.6.0/gems/arduino_ci-0.3.0/lib/arduino_ci/arduino_installation.rb to update DESIRED_ARDUINO_IDE_VERSION.

Would it be reasonable to allow this to be configurable in .arduino-ci.yml?

[ianfixes]

I'm trying to put a fine point on what the fix should be here. arduino_ci is only one part of the CI configuration -- even though it's often invoked as a one-liner in the sample scripts, it's not meant to be a replacement for the shell scripting that one would have to perform in a .travis.yml (or similar) file. So the automatic installation of libraries or the IDE itself is meant as a failsafe or a convenience and not a replacement for explicit environment setup.

DESIRED_ARDUINO_IDE_VERSION is really a guarantee that the version we download matches the CLI behavior that arduino_ci codes against -- I'd be nervous about allowing that to be set to an arbitrary value as I have no guarantee that the CLI will be compatible.

Perhaps the better solution here is to detect 64-bit-only OSes and handle that. And possibly to bump the supported version from 1.8.6 to a more modern version. Does 1.8.13 download & run correctly in 32-bit OSes?

[jgfoster]

According to the downloads page, Arduino IDE version 1.8.13 runs on Window 7 and later, macOX 10.10 and later, and Linux 32-bit and 64-bit. While I have Windows 10 64-bit, when I run the Arduino IDE installer it puts the executable in C:\Program Files (x86) which is the 32-bit directory so I assume that it is running a 32-bit app even on the 64-bit OS. Thus, I think updating to 1.8.13 would be safe and sufficient and this issue could be closed.

[per1234]

I haven't tried 32 bit, but I closely follow the Arduino forum and the Arduino IDE's issue tracker, and this is the sort of thing you definitely hear about when compatibility is lost. So I think there is no problem with new IDE versions and 32 bit OS.

The most recent losses I'm aware of were Windows XP/Vista and the older macOS versions, which was caused by Go dropping support, and subsequently breaking compatibility with those OS versions:

• 1.8.12 IDE: java.io.IOException: Cannot run program "C:\Program Files\Arduino\arduino-builder" arduino/Arduino#10018
• Mac OS X before 10.10 - dynamic linking broken arduino/Arduino#10047

[ianfixes]

Well... we're off to a rocky start, immediately encountering arduino/Arduino#9351

I was planning to go all-in on #206 after bumping the version, so this is a setback. But this seems like the appropriate next step.