# modelx v0.6.1 (29 April 2020)¶

This release is for a bug fix.

# modelx v0.6.0 (27 April 2020)¶

This release implements a new error mechanism for tracing errors raised in formula execution. The error messages are also improved.

## Enhancements¶

Formula error

When an error is raised during formula execution, the new default behaviour of modelx is to raise FormulaError, instead of raising the original exception. The error message of the FormulaError shows the error message from the original exception, followed by a traceback of modelx elements, and the source code of the formula the exception is raised from. To retrieve the original exception, use get_error() function. This default behaviour can be altered by the user by passing False to use_formula_error() function, in which case the original errors are raised. get_traceback() function returns the traceback information as a list of tuples. Each tuple represents a call to a formula stacked in the execution callstack when the error is raised. The first element of the tuple is an element of a modelx object, which is an element of a Cells in most cases. The second element of the tuple is a line number in the formula, indicating where the call to the next formula is or, in the case of the last formula, where the error happens. The line number of the last formula can be 0 if the error happens before or after the execution of the formula.

The last error information, which can be retrieved by get_error() and get_traceback(), is cleared at the next formula execution.

## Backward Incompatible Changes¶

• Implicit conversion of a Cells with no parameters to its value upon assignment to a Cells is now removed.

## Bug Fixes¶

• Broken internal state due to failed formula execution.