Hello,
Natalia I don't think this is a known bug (few people use Float and Fraction in Pharo).
The RBParser parse your floating pointers as Fraction and not as Float (I don't know why).
In the debugger the bytecode pc to source code pointer is mapped by printing the AST. In this case, the AST node (RBLiteralNode) for your float holds a Fraction. The code to print a literal node is as follow:
visitLiteralNode: aLiteralNode
aLiteralNode value isLiteral
ifFalse: [ ��self writeString: '''<an unprintable nonliteral value>''' ]
ifTrue: [ self writeString: aLiteralNode token storeString ]
and isLiteral answers always false for a Fraction.
A temporary patch consists in adding the method
Fraction>>isLiteral
�� �� ^ true
Then you can debug your code.
However, I think a real patch would consists in adding the method isLiteral in Fraction but with correct code to answer true only if the fraction can be a literal. Something similar to Float>>#isLiteral.