indent
The indentation of a line is wrong.
Indentation is exactly 2 spaces per level. A tab in indentation, an odd width, or an indent where no block opens is an indent error. A comment line is not checked, so it never opens or closes a block.
Example
Check this program to see the diagnostic.
# package p
define Half
result 0.5
Diagnostic
p/p.synod:3:4: error[indent]: indentation is not a multiple of 2 spaces
Fix
Indent each level by exactly 2 spaces.
# package p
define Half
result 0.5