Unexpected Characters in boot_out.txt

[safferyj]

CircuitPython version

Adafruit CircuitPython 9.1.0-beta.0 on 2024-03-28; Adafruit Feather ESP32-S2 Reverse TFT with ESP32S2
Adafruit CircuitPython 9.1.0-beta.0 on 2024-03-28; FeatherS2 Neo with ESP32S2

Code/REPL

#

Behavior

boot_out.txt file contains 8 unexpected characters betweeen the newline after the UID and the start of "boot.py output". The characters (in hex) are: 1b 5b 32 4b 1b 5b 30 47.

Description

May be reproduced with no code.py file, and any boot.py file, including an empty boot.py. If there is no boot.py, then there are no unexpected characters.

Additional information

[RetiredWizard]

Esc [2K is the ansi terminal sequence to erase the current line and Esc [0G places the cursor at column zero.

[jepler]

    mp_hal_stdout_tx_str(line_clear);
    mp_hal_stdout_tx_str(_current_executing_filename);
    serial_write_compressed(MP_ERROR_TEXT(" output:\n"));

The "line clear" code is written by this line in main.c. It was added by @bill88t in 722d8ff for #8725 and this code applies to running both boot.py and code.py. You can check that PR for more background about why it was added; It might be possible to use a different call that bypasses the output capture for boot_out.txt, but I didn't investigate it any further than that.