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A long engineering task is complete only when linked implementation, caller, test and documentation requirements all hold.
A long engineering task can fail after several individually plausible steps. Comparing GLM-5 with GLM-4.7 therefore needs a task with intermediate dependencies and a final state that can be checked.
Read each model’s intended scope
The GLM-5 card targets complex systems engineering and long-horizon agentic tasks. The GLM-4.7 card emphasizes coding and multi-step tool work. These descriptions motivate a comparison, but they do not establish an automatic winner for a private repository.
The official GLM-5 repository provides the release’s artifacts and usage references. Record an exact checkpoint rather than assuming that a hosted alias has remained fixed while the experiment was being prepared.
Choose a migration with linked stages
Use a fictional configuration library that must replace an implicit default with an explicit option. The model needs to update the parser, internal representation, callers, tests and user-facing example.
Each stage depends on the others. A parser accepting the new option is insufficient if callers still construct the old representation. A rewritten example is misleading if the implementation does not actually support the documented behavior. This creates a task that cannot be reduced to one correct function.
Define milestones as evidence, not narrative
| Milestone | Required evidence |
|---|---|
| Understand the change | Old and new representations identified |
| Implement the option | Parser and representation agree |
| Update callers | No remaining incompatible construction |
| Preserve supported behavior | Regression checks remain valid |
| Finish documentation | Example matches the accepted implementation |
A statement that a milestone is complete should be backed by the corresponding file change or check. Count the whole task as complete only when its linked requirements all hold.
Diagnose long-horizon failure modes
A model may start correctly and later forget a protected behavior. It may reinterpret the requirement halfway through, repeatedly edit the same file or stop after reporting a plan. These outcomes differ from an isolated syntax error.
Preserve the sequence of proposed changes and actual tool observations. If the environment withheld a necessary file, separate that limitation from loss of requirement continuity. If a model claims tests passed without a test observation, the claim remains unsupported.
Choose based on the finished repository state
Evaluate both checkpoints with the same starting repository, available information, tool interface and overall attempt policy. Use each model’s valid prompt format. Do not grant one model extra human corrections without disclosing them.
Keep accepted final states, abandoned attempts and regressions in the comparison. A successful run supports a bounded conclusion about this migration structure. It does not prove that GLM-5 always finishes long projects, that GLM-4.7 is limited to short tasks or that a public benchmark measured the same repository and acceptance process.