Field note / 03

Read an error message carefully.

Copy the exact wording into your local notes before interpreting it. The first error often explains the ones that follow.

Find the boundary

Identify the operation that failed: reading a file, parsing an input, or validating a value. Check its documented preconditions.

Make a smaller case

Reduce the input until the same error still appears. Change one property and record whether the result changes.

Check the ordinary causes

Version mismatches, missing files, and unexpected encodings are worth checking early. A reproducible observation is more useful than a confident guess.