Opening example with `.pde` file extension fails silently

[lmtanco]

Describe the problem

If the example for a library has .pde file extension, Arduino IDE will silently fail to open it.

To reproduce

1. Use Library Manager to install version "1.1" of the "TimerOne" library from Library Manager
2. Select Examples > TimerOne > Interrupt

🐛 The example doesn't open. There is no communication of a problem.

Expected behavior

Arduino IDE opens all valid example sketches, regardless of whether they use a deprecated file extension.

Arduino IDE version

2.0.0-beta.11

Operating system

• macOS
• Windows

Operating system version

• Windows 10
• macOS (not stated)

Additional context

On the Arduino forum, user in0 has reproduced the error on Windows and provides additional info:

I can reproduce it. You can see the problem when run from the command line:

root ERROR Request cloneExample failed with error: ENOENT: no such file or directory, rename 'c:\Users\<user name>\AppData\Local\Temp\.arduinoIDE-unsaved2021827-16716-11heo0w.vdua\Interrupt\Interrupt.pde' -> 'c:\Users\<user name>\AppData\Local\Temp\.arduinoIDE-unsaved2021827-16716-11heo0w.vdua\Interrupt\Interrupt.ino'

It's trying to rename the sketch in the temporary folder rather than in its true path under the library installation.

I don't have this problem with a standalone sketch using the .pde file extension.

Additional Reports

• https://forum.arduino.cc/t/why-some-library-examples-do-not-load-in-arduino-ide-2-0/1104079/1
• https://forum.arduino.cc/t/exmaple-not-loading/1069511
• https://forum.arduino.cc/t/in-version-2-0-0-i-cant-open-accelstepper-examples/1041358
• https://forum.arduino.cc/t/newping-librarys-example-code-wont-open/1036177
• https://forum.arduino.cc/t/ds3231-of-example-frome-custom-libraries-is-not-open/934173
• https://forum.arduino.cc/t/ide-wont-load-sketches/1112447

Workaround

Rename the example sketch to use the .ino file extension.

Issue checklist

• I searched for previous reports in the issue tracker
• I verified the problem still occurs when using the latest nightly build
• My report contains all necessary details

[ubidefeo]

hi @lmtanco
Thank you for the kind words :)

This issue is in our backlog, but since more and more 3rd party developers are updating their libraries and examples to comply with specifications, we gave it very low priority.
The .pde extension for Arduino has been long deprecated, and we feel that if we leave it as is nobody will care to bring their Sketch code into 2021 and beyond :)

I have created a PR to Paul with the extensions updated.
PaulStoffregen/TimerOne#54

Thank you

[mrkylegp]

I have this issue in 2.0.2. Can't open a .pde example for the PCM library. Very frustrating.

[KurtE]

Just checked again, with yesterday's daily build (after 2.0.2) and still has issue.

This time with the Radiohead library.

[mrkylegp]

@KurtE Yep, it's very frustrating. Not exactly an upgrade IMO since several of the libraries I use have .pde files that wont open and the developers aren't going to be updating these libraries again. I'm back to using the older IDE for now.

[nbourre]

My suggestion would be to detect if the library's examples are using the obsolete format, if so ask the user if he would like to upgrade them.

[wh201906]

I think this has been fixed in commit 0ab2826.
In the code before this, the copy() will rename the .pde into .ino, but it will try to access the new file with the old .pde extension, so it fails.
I have tested this bug on v2.1.0 and it was fixed.

[lmtanco]

Apologies for not closing this before.

This works perfectly now (v2.2.1). Even if the example has .pde extension, it will open it, then it will ask the user if they want to change its extension.

Tested on macOS Apple Silicon Ventura 13.4 (screenshot) and Windows 11.