Spurious "Please select a Port before Upload" error with Upload Using Programmer

[fpgaminer]

Tested on nightly: 28 September 2018 3:2:58 GMT
OS: macOS 10.14

The Bug
Attempting to upload a sketch using USBtinyISP as the selected programmer will always fail on macOS with the error "Please select a Port before Upload". This is a bug because, as far as I understand, USBtinyISP is a USB device, not serial, so it is impossible to select a Port for it (this is at least true of the Adafruit Trinket).

This is a regression bug; uploading works fine on 1.6.13.

According to another party this bug is not present on Windows.

Steps to reproduce:

• Write an LED blink sketch (or any sketch)
• Select Tools->Board->Adafruit Trinket (ATtiny85 @ 8MHz)
• Select Tools->Programmer->USBtinyISP
• Click Upload

Error Message:

Please select a Port before Upload

Expected Behavior:

Arduino IDE should not require a Port to be selected when the programmer is USBtinyISP.

Opinion:

Looking through the code, it seems this was a "feature" added some point after v1.6. Before, the code didn't care if there was a serial port or not and would just blunder forward through newUploader anyway (with boardPort left as null). The correct fix, I guess, is for getUploaderByPreferences to be aware of which Programmer is selected and whether it needs a serial port or not. Alternatively this feature could simply be rolled back (I've found no way to work around it; so it breaks Arduino 1.8 on macOS).

[facchinm]

It looks like the bug starts from 4ccf9bb (included in #7958)
@PaulStoffregen the best way to tackle this could be parsing the upload rule in advance to decide if it's ok to fail for the missing serial port, otherwise I think we should revert to the old behaviour.
@fpgaminer the patch is contained in both 1.8.6 and 1.8.7 so the newest stable version you can use at the moment is 1.8.5 .

[per1234]

The workaround is to select any port from the Tools > Port menu. It doesn't matter what port that is. That only needs to be done once. Of course that requires that either the computer has a native serial port or that the user can connect some device to the computer that creates a port.

The bug does occur on Windows. Steps to reproduce it:

1. Click the link at the line following [b]File > Preferences > More preferences can be edited directly in the file[/b]. This will open the Arduino15 (or similar name) folder.
2. Close the Arduino IDE.
3. Rename preferences.txt to preferences.txt.bak. This is necessary to emulate a fresh IDE installation, where no port has ever been selected from the Tools > Port menu.
4. Start the Arduino IDE.
5. Sketch > Upload Using Programmer (or standard upload to a board that doesn't define upload.protocol, such as the ATtiny85-based Trinket).

[PaulStoffregen]

Opps, sorry for this. Looking at it now.

I don't personally own a Trinket or USBtinyISP programmer. I can get them if needed, but that will take several days.

Before we fully revert this, please consider the Arduino forum would repeatedly get the same new user question, where avrdude would try to access COM1. We really should find a way to fix this, but avoid the extremely common case where first time users get stuck only because the default was COM1 and they use Windows and their PC really does have a COM1 port (usually on a motherboard header without any cable connected to the outside world).

[PaulStoffregen]

@fpgaminer - I'm trying to follow your steps to reproduce the problem. But I'm not able to do step 2:

Select Tools->Board->Adafruit Trinket (ATtiny85 @ 8MHz)

It does not appear in Tools > Boards. I can not find any installation for it in Tools > Boards > Boards Manager.

Perhaps at some point you added another URL to the "Additional Boards Manager URLs" in File > Preferences? Any chance you could look at that list and give me the URL needed to be able to install support for Trinket?

[per1234]

@PaulStoffregen here it is:
https://adafruit.github.io/arduino-board-index/package_adafruit_index.json
It's in the "Adafruit AVR Boards" package.

You don't need the hardware to reproduce the bug.

[PaulStoffregen]

Confirmed, I can reproduce the problem here on a Linux system.

Still looking for a clean way to fix this and prevent the extremely common case of avrdude cryptic (and very slow) messages when COM1 exists but isn't connected to anything.

[fpgaminer]

Thank you for taking a look at this bug!

I'm not familiar enough with the codebase to contribute meaningfully beyond the bug report, but I'm curious; is getUploaderByPreferences able to get information about the currently selected programmer? If so, I noticed that in the packaged programmers.txt a communication option is defined for most programmers specifying either serial or usb. Perhaps that value could be checked, and if it's not serial then don't require that a serial port is selected?

[PaulStoffregen]

Saw that too. But some done define it at all, so I want to dig into this a little more. Sadly, I have to do customer service stuff for the rest of today (PJRC is a tiny company, only 4 people...) Will look at this again tomorrow morning.

[chrisjsmith]

Confirmed reproduced this on windows 10 / Arduino 1.8.7 with USBasp

[ladyada]

@PaulStoffregen hiya will you be able to take a look at this bug? some customers are asking me about it. perhaps for now i can tell them to just use arduino 1.8.6

[ladyada]

FYI this also would affect Arduino Gemma because it uses the same technique