Error Conditions

Circular Dependency Detected

Condition: Dependency graph contains cycles

Detection: digraph_utils:topsort/1 returns false and digraph_utils:is_acyclic/1 returns false

Error Format:

{cycles, [[<<"app1">>, <<"app2">>, <<"app3">>], ...]}

Error Message:

Dependency cycle(s) detected:
applications: app1 app2 app3 depend on each other

Example:

app1 depends on app2
app2 depends on app3
app3 depends on app1
→ Cycle: [app1, app2, app3]

Recovery: None; must break the cycle in dependencies

Package Not Found in Registry

Condition: Hex package doesn't exist

Error Format:

{missing_package, Package, Version}
{missing_package, Package}

Error Message:

Package not found in registry: jsx-3.1.0
Package not found in registry: nonexistent_package

Recovery: Fix package name or check Hex registry

Bad Version Constraint

Condition: Invalid version specification

Error Format:

{bad_constraint, Name, Constraint}

Error Message:

Unable to parse version for package jsx: ~~>3.1.0

Recovery: Fix version constraint syntax

Package Not Buildable

Condition: Hex package exists but isn't rebar3-compatible

Error Format:

{not_rebar_package, Package, Version}

Error Message:

Package not buildable with rebar3: old_package-1.0.0

Recovery: Use different version or different package

Failed to Load Registry

Condition: Cannot download Hex registry

Error Format:

{load_registry_fail, Dep}

Error Message:

Error loading registry to resolve version of jsx. Try fixing by running 'rebar3 update'

Recovery: Run rebar3 update or check network connection

Dependency Application Not Found

Condition: Dependency fetched but application not in expected location

Error Format:

{dep_app_not_found, AppDir, AppName}

Error Message:

Dependency failure: Application my_dep not found at the top level of directory /path/to/dep

Possible Causes:

• Dependency doesn't have .app.src file
• Application name doesn't match directory name
• Dependency is not an OTP application

Recovery: Fix dependency structure or use different version