parapluu/Concuerror

Concuerror is a stateless model checking tool for Erlang applications, designed to detect race conditions and deadlocks by exploring concurrent execution interleavings. The system provides both command-line and GUI interfaces, featuring Dynamic Partial Order Reduction (DPOR) algorithms to efficiently analyze concurrency. It includes a comprehensive test suite that validates the tool's behavior against various Erlang constructs, real-world libraries, and concurrency litmus tests.

16 changes.

This period marks the initial creation and expansion of the Concuerror project, a stateless model checking tool for Erlang. The work focused on establishing the core architecture, build infrastructure, and comprehensive test suites to verify concurrency analysis and dynamic partial order reduction (DPOR) algorithms.

8 changes.

This period focused on significantly expanding test coverage across the codebase, particularly for concurrency and edge cases using Concuerror. Key additions included new test suites for gproc and poolboy, while existing tests for options and corner cases were restructured and deepened. Additionally, code coverage thresholds were enforced to maintain high standards.

7 changes.

This period focused on significantly expanding the project's test coverage by introducing new test suites for Erlang concurrency, output formatting, and specific modules like timer and maps. The work also included adding build scripts for documentation and code coverage, as well as implementing bash completion to improve the command-line experience.

Users can now use the bash completion script for the concuerror command, enabling tab-completion for all available options and arguments. This improves the command-line experience by providing context-aware suggestions for flags like --dpor, --scheduling, and file paths.

_resources/bash\completion · high confidence

A new test suite has been added to run Erlang concurrency litmus tests using the Concuerror tool. The suite includes a Makefile to manage the external test repository, a shell script to handle version checks and execution, and an escript that orchestrates the testing of various concurrency scenarios such as registry, timer, signal, and process tests. This allows users to verify concurrent behavior in their Erlang applications against known litmus test cases.

tests-real/suites/erlang-litmus · high confidence

The \resources/old\_source\ directory now contains the source code for Concuerror, a static analysis tool for Erlang applications. This includes the main CLI and GUI entry points (\concuerror.erl\, \concuerror\_gui.erl\), the instrumentation engine (\concuerror\_instr.erl\), dependency analysis (\concuerror\_deps.erl\), error handling (\concuerror\_error.erl\), logging (\concuerror\_log.erl\), and supporting modules for process actions, LIDs, and I/O. A BSD-style LICENSE file has also been added to the directory.

_resources/old\source · high confidence

Added a new Erlang module (resources/flanagan.erl) containing a prototype implementation for the Flanagan tool, including state records, command execution logic, and process simulation functions. Additionally, added a new markdown file (resources/how-to-release.md) providing step-by-step instructions for preparing and publishing a new release of Concuerror, including versioning, tagging, and Hex publishing steps.

resources · high confidence

A new test suite for the Concuerror model checker has been added to the resources/perm\_tests directory. This includes a run\_perm\_tests shell script and multiple Erlang modules (such as complete\_test\_3, conditional\_readers\_3, depend\_4\_1, depend\_6\_1, etsi, and readers\_2/3) that define specific concurrency scenarios. These tests are designed to run exhaustive scheduling checks against the Concuerror tool to verify correct behavior under various interleavings.

_resources/perm\tests · high confidence

Introduced a new generic registration server (\reg\_server\) that manages process registrations with a maximum capacity (currently set to 2). The server supports attaching, detaching, and pinging registered processes, and includes a comprehensive test suite (\reg\_server\_tests\) covering start/stop cycles, concurrent operations, and edge cases like exceeding the attachment limit.

resources/tdd · high confidence

The repository was initialized with a new build system using Rebar3, including a Makefile for common tasks (build, test, lint, dialyze) and a rebar.config file that defines dependencies (getopt), compiler options, and profiles for development, documentation, and testing. The project also includes standard configuration files such as .editorconfig, .gitignore, elvis.config for Erlang style checking, and a CHANGELOG.md following the Keep a Changelog format. Additionally, contributor guidelines (CONTRIBUTING.md) and a Code of Conduct (CODE\_OF\_CONDUCT.md) were added to support community involvement.

(repo-wide) · high confidence

Concuerror is introduced as a stateless model checking tool for Erlang programs. This change adds the core source files, including the main entry points for command-line and Erlang API usage, the instrumenter for analyzing code, the scheduler for exploring interleavings, and the logger for reporting results. The tool supports analyzing concurrent Erlang applications by detecting race conditions and deadlocks.

src · high confidence

The project now includes EDoc-compatible documentation files (overview.edoc) and a Makefile to automate the generation of HTML documentation. This change introduces a new build target for generating the API specification and sets up the necessary build dependencies and ignore rules for generated files.

doc · medium confidence

Added the 'DPOR\_paper\_material' directory containing a README guide for the Concuerror tool's experimental Dynamic Partial Order Reduction (DPOR) features, along with several Erlang source files (foo.erl, foobar.erl, my\_test.erl) and shell scripts (run\_dialyzer.sh, run\_filesystem.sh, run\_indexer.sh, run\_last\_zero.sh, run\_readers.sh, run\_rush\_hour.sh) designed to benchmark and compare different DPOR algorithm variants (o-DPOR, s-DPOR, DPOR) on various concurrency examples.

_resources/DPOR\_paper\material · medium confidence

Three new executable scripts have been added to the 'priv' directory to support the build and documentation processes. 'concuerror' is a wrapper script used to collect code coverage data, 'generate\_option\_docfiles' creates documentation for options, and 'generate\_version\_hrl' generates header files containing OTP version definitions.

priv · high confidence

The \resources/old\_include\ directory now contains archived header files (\gen.hrl\, \gui.hrl\, \instr.hrl\) that preserve the original definitions for the Concuerror tool's general configuration, GUI layout, and instrumentation logic. These files are moved out of the active build path to keep the main codebase clean while retaining the legacy definitions for reference or compatibility.

_resources/old\include · high confidence

The cover-report script now enforces minimum code coverage thresholds, failing with an error if individual module coverage drops below 85% or total coverage drops below 94%. This ensures that the project maintains a high standard of test coverage, with the script exiting with a non-zero status code if these thresholds are not met.

cover · high confidence

The reference output files for the gproc test suite (t\_reg\_or\_locate2, t\_simple\_reg, t\_simple\_reg\_or\_locate, test3, and test4) have been updated. These changes correspond to the fix for ETS tids in heir messages, ensuring the test expectations align with the corrected behavior.

tests-real/suites/gproc/ref · high confidence

Add Erlang test cases for dets race conditions; Add Makefile-based test suite for the makefile component; Add gproc test suite with Concuerror verification; Added EUnit tests for time formatting and option validation; Added Python 3 test runner and test templates for Concuerror; Added exhaustive concurrency test for message delivery scenarios; Added output test suite for ConcuError; Added syntax instrumentation tests for Erlang constructs; Added test coverage for Concuerror bounding algorithms; Added test coverage for Erlang timer and maps modules; Added tests for the poolboy suite; Added unit tests for Concuerror internal modules; Expanded Concuerror test coverage for advanced concurrency scenarios; Expanded DPOR test coverage for concurrency analysis; Expanded and restructured option validation tests; Expanded test coverage for concurrency and error handling.

The Ruby dependencies for the documentation site have been updated to their latest compatible versions. This includes bumps to key libraries such as nokogiri, activesupport, faraday, rexml, commonmarker, and addressable, ensuring the site uses the most recent, stable releases of these tools.

(dependencies) · high confidence

Written by watchdog.canine.dev from the codebase's own history, inside the signed delivery this page is composed from.

• CAI 66 → 73 (+6.8)
• Rubric changed (rubric-2026.08.19 → rubric-2026.09.15) — scores are not directly comparable.

• Code Health 86 → 84 (-2.4)
• Architecture 100 → 100 (+0.0)
• Maturity 55 → 60 (+5.9)
• Readiness 64 → 80 (+15.9)
• Security 83 → 86 (+2.2)
• Event Sourcing 100 → 100 (+0.0)

• Concentrated knowledge decay
• Coverage not included — suite not readable by the collector
• Dependency hygiene not measured — dependency manifest found but not parsed for hygiene
• FileTooLong: old_source/concuerror.erl (resources/old_source/concuerror.erl)
• FileTooLong: old_source/concuerror_gui.erl (resources/old_source/concuerror_gui.erl)
• FileTooLong: old_source/concuerror_rep.erl (resources/old_source/concuerror_rep.erl)
• FileTooLong: old_source/concuerror_sched.erl (resources/old_source/concuerror_sched.erl)
• High: security finding (details withheld)
• High: security finding (details withheld)
• High: security finding (details withheld)
• High: security finding (details withheld)
• Largest orphaned file (resources/old_source/concuerror_gui.erl)
• Largest orphaned file (resources/old_source/concuerror_sched.erl)
• Largest orphaned file (src/concuerror_callback.erl)
• No exposed public API
• Off-boarding risk: anonymized user #1
• Test reliability not included
• The README links to a GitHub clone command but does not mention Hex.pm availability or how to add Concuerror as a dependency in an Erlang project. (docs/download.md)
• The heisenbug tutorial is excellent, but it ends mid-sentence ('Could Concuerror find the concurrency bug it had?') and clips before explaining how to run Concuerror with EUnit on single tests rather than a suite. (_posts/2017-10-08-concuerror-eunit.md)
• TooManyMethods: concuerror_callback (src/concuerror_callback.erl)
• …and 8 more

• Coverage not measured — no coverage collector is wired up
• Documentation: no installation or build instructions
• Documentation: no usage examples
• Duplicated block (13 lines × 2) (src/concuerror_logger.erl)
• Duplicated block (18 lines × 2) (resources/perm_tests/src/depend_4_1.erl)
• Duplicated block (21 lines × 2) (tests-real/suites/options/src/first_and_other_deadlock.erl)
• Duplicated block (5 lines × 13) (resources/perm_tests/src/complete_test_3.erl)
• Duplicated block (5 lines × 2) (src/concuerror_callback.erl)
• Duplicated block (5 lines × 2) (src/concuerror_dependencies.erl)
• Duplicated block (5 lines × 2) (src/concuerror_dependencies.erl)
• Duplicated block (5 lines × 4) (resources/perm_tests/src/complete_test_3.erl)
• Duplicated block (7 lines × 2) (resources/erlang_questions/dets_bugs/alt_dets_bugs.erl)
• Duplicated block (7 lines × 2) (resources/perm_tests/src/depend_6_4.erl)
• Duplicated block (7–8 lines × 3) (resources/perm_tests/src/depend_4_1.erl)
• Duplicated block (8 lines × 2) (resources/perm_tests/src/depend_6_2.erl)
• Edited copy of a member (18 corresponding lines) (resources/perm_tests/src/depend_4_1.erl)
• Further orphaned files (smaller)
• High: security finding (details withheld)
• High: security finding (details withheld)
• High: security finding (details withheld)
• …and 84 more

Written by watchdog.canine.dev from the codebase's own history, inside the signed delivery this page is composed from.

parapluu/Concuerror was measured the same way every project in this corpus was: the same rubric, at a pinned commit, with the result published in full. Point a surveyor at a repository you know and see whether you agree with it.