Installing Arduino megaAVR Boards breaks ATTinyCore ISP sketch uploads

[JChristensen]

Steps to reproduce:

1. Install Arduino 1.8.9.
2. Install ATTinyCore 1.2.5 using the Boards Manager Installation instructions on GitHub.
3. Using the following settings on the Arduino Tools menu and an Adafruit USBtinyISP programmer, upload a sketch to an ATtiny85:

Board: ATtiny25/45/85
Chip: ATtiny85
Clock: 1MHz (internal)
B.O.D. Level: B.O.D. Disabled
Save EEPROM: EEPROM retained
Timer 1 Clock: CPU
LTO: Disabled
Programmer: USBtinyISP (ATTinyCore)

4. Upload succeeds, see attached verbose upload output (upload-ok.txt, attached)
5. Using the Boards Manager, install Arduino megaAVR Boards by Arduino version 1.8.3.
6. Retry step (3) above; upload fails, see attached output (upload-err.txt, attached)
7. Note that in upload-err.txt, avrdude runs from a different location than in upload-ok.txt. Yet the avrdude referenced in upload-err.txt can be used successfully from the command line (see cmdline.txt, attached).
8. Remove Arduino megaAVR Boards and the ATtiny upload works again.
   upload-ok.txt
   upload-err.txt
   cmdline.txt
   Edit: This issue does not occur if a USBasp programmer is used.

[per1234]

It looks like a duplicate of arduino/ArduinoCore-avr#91

Yet the avrdude referenced in upload-err.txt can be used successfully from the command line (see cmdline.txt, attached).

The cmdline.txt output shows it's using avrdude 6.2:

avrdude: Version 6.2

[JChristensen]

It looks like a duplicate of arduino/ArduinoCore-avr#91

It's the other way around, yes? For me, in the IDE, 6.3 worked while 6.2 failed. Yet 6.2 seemed OK on the command line.

[per1234]

For me, in the IDE, 6.3 worked while 6.2 failed.

No. The avrdude version used in upload-ok.txt is the one bundled with Arduino IDE 1.8.9/Arduino AVR Boards 1.6.23, which is avrdude 6.3.0-arduino14. The avrudude version used in upload-err.txt is avrdude 6.3.0-arduino16.

Yet 6.2 seemed OK on the command line.

As is expected. The bug is only in avrdude 6.3.0-arduino16.

[JChristensen]

Not sure where the 6.2 came from. I cannot duplicate that now. Maybe best to ignore the command line scenario. Original issue remains, installing Arduino megaAVR Boards breaks ATTinyCore uploads. Both report 6.3-20171130 in the IDE but with megaAVR installed, avrdude runs from a different location.

[facchinm]

@JChristensen the TinyCore doesn't specify any dependency tool in its json

        {
          "name": "ATTinyCore",
          "architecture": "avr",
          "version": "1.2.5",
          "category": "Contributed",
          "help": {
            "online": ""
          },
          "url": "https://github.com/SpenceKonde/ATTinyCore/archive/1.2.5.tar.gz",
          "archiveFileName": "ATTinyCore-1.2.5.tar.gz",
          "checksum": "SHA-256:db0b7fca838436f04337d4faad47c109e10add1f8b716d689cec4858c8223afc",
          "size": "5569027",
          "boards": [
            {"name": "ATtiny441"},
.....
            {"name": "ATtiny43"}
          ],
          "toolsDependencies": []
        }
      ],
      "tools": []
    },

so the IDE picks (what it thinks to be) the best program that matches avrdude when requested.
Since megaAVR core ships with avrdude-6.3.0-arduino16 (which still suffers from arduino/ArduinoCore-avr#91 ) that tool becomes the preferred one.
I'm going to publish an updated megaAVR core shipping with avrdude-6.3.0-arduino17 (which fixes the issue).
In the meantime, to overcome your problem, you can modify TinyCore's platform.txt so this line becomes tools.avrdude.path={runtime.tools.avrdude-6.3.0-arduino14.path}

[JChristensen]

@facchinm thank you for the explanation. I don't actually use the megaAVR core, so my fix right now is to just remove it and I'm happy with that. I only had it installed to work on an issue with one of my libraries that someone had reported. It was still installed when I went back to do some work with the ATTinyCore and I was surprised when the upload failed. That's when I found the conflict between the two cores and raised the issue.

[MCUdude]

It's fixed in the latest 1.8.4 release!

[facchinm]

Fixed by core 1.8.5