GCAM v7.1 Documentation: Debugging

Documentation for GCAM
The Global Change Analysis Model

View the Project on GitHub JGCRI/gcam-doc


Debugging: common issues

Types of messages in GCAM

GCAM prints different levels of messages to help identify issues.

Configuration/input file errors

Problem: Immediate crash

Message immediately follows “Parsing input files…“

Message: ERROR: Unexpected XML Read Exception

Possible causes:

Problem: Crash while reading ScenarioComponents XML files

Message immediately follows the parsing of an individual input file.

Message: ERROR: Unexpected XML Read Exception

Possible causes:

Problem: Crash after parsing, but before first period

Message immediately follows “XML parsing complete.”

Message: ERROR: Could not find global technology for...

Possible causes:

Problem: Message printed to screen about “explicitly creating a market for CO2”

Model will not abort, but will have problems solving later.

Message: Using negative-emissions-final-demand with target-finder without explicitly creating a market for CO2 may hinder solution performance. Please read in a policy file with a zero tax.

Cause: A carbon price must be read in with target finder in order to set up dependencies.

Calibration and solver failures

Calibration failures

A calibration failure means that the read-in values for supply and demand do not match.

Message: Model did not calibrate successfully in period...

Cause: Unbalanced supply and demand in calibration years. Check all calibration data, including coefficients to debug.

Solver failures

A solver failure means that the model cannot find a set of prices where supply and demand are equal for all commodities.

Message: Model did not solve within set iteration...

Note: solution issues can be difficult to decipher

Things to try: