OMNEST 6.5 (October 2026)

This is primarily a bugfix release. The main new features are clipping support for canvas figures, reporting of configuration entries that have no effect (useful e.g. when porting models to a new version of a model library), and the ability of the NED documentation generator to link to the separately generated documentation of referenced projects and to produce PNG images. The main bugfix areas are the correctness of recorded and analyzed results (units of count scalars, field scalars and dB; warm-up period handling), WATCH() and inspector display, connection drawing in Qtenv, rendering in the graphical NED editor, and matplotlib and Pandas compatibility in the Analysis Tool and the Python library.

Simulation kernel:

  • Canvas: Shape figures can now clip the rendering of their figure subtree to their own shape: setClipChildren(true) in C++, clipChildren=true in @figure. The clip region is the geometric interior of the shape (excluding the outline), and nested clip regions are intersected.

  • Fixed several WATCH() problems, including missing support for some standard library types (e.g. std::deque, std::optional, smart pointers) and a compile error for std::vector<bool>.

  • Fixed opp_typename() dropping template arguments from type names, which caused name collisions in WATCH(). It now returns full type names.

  • Fixed cObject::dropAndDelete() leaving a dangling pointer in the owner module's list of owned objects, which caused a crash later.

  • Fixed the count and totalCount recording modes recording the unit of the statistic, which made tools that convert to base units produce bogus numbers (#1513). The unit is also removed when loading older result files.

  • Fixed statistics added dynamically via cEnvir::addResultRecorders() with a @statisticTemplate ignoring warmup-period and the autoWarmupFilter key (#1522).

  • Fixed a crash when something was logged before the eventlog file was opened, e.g. from lifecycle listeners (#1496).

Configuration:

  • Added the unused-entry-check configuration option (off, warning, error; default: warning), which reports configuration entries that have had no effect, e.g. because the parameter, or a module in the entry's path, was renamed or removed. The companion option unused-entry-check-time (initialization or end, default: end) selects when the check is done; checking at the end also covers modules created dynamically. If the run stops with an error, the entries that have had no effect until then are reported as a warning after the error message, because a stale entry is often the cause of an error that looks unrelated.

  • Fixed shadowed duplicate keys being recorded into the run header of result files (and printed by -q runconfig).

NED:

  • Fix: Removed the conversion from plain dB to x (dimensionless ratio), because it was ambiguous: the unit alone cannot tell whether a value denotes an amplitude ratio (20log10(x)) or a power ratio (10log10(x)). Assigning a dB value to an @unit(x) parameter is now an error (#1514).

MSG files, opp_msgc:

  • Fixed some generated descriptors displaying values inconsistently or as "(unprintable)", e.g. for typedefs of standard library containers such as INET's Ipv4AddressVector.

  • Fixed parsim unpacking of std::vector<bool> fields not compiling (#1421).

Qtenv:

  • Implemented clipping of canvas figures. Tooltips and object selection honor the clipping, and zoom-to-fit ignores the clipped-away areas.

  • Generic Object Inspector usability improvement: The overlay on hovered tree rows now holds a strip of mode buttons (Children, and the Details variants Grouped, Flat, Inheritance and Packet) instead of the Children/Details toggle, so a row can be switched to any mode with a single click.

  • Fixed connections between two gates of the inspected compound module being drawn as an arrow ending in the middle of the module (#1399), and only half of the line being drawn for two-way connections whose both ends are on the same module.

  • Warnings (e.g. those about unused configuration entries) are now written to the log window.

Command-line Tools:

  • opp_neddoc: Added the -l, -r and --raster-images options for the new NED Documentation Generator features (see below). Fixed errors not being reflected in the exit code.

  • opp_makemake: Fixed large projects (e.g. INET) failing to link on Windows with "Argument list too long" when the OS environment variable was unset (#1506).

Python library:

  • Pandas 3 is now supported (#1482). Fixed bar, histogram, box-and-whiskers, line, scatter and 3D charts failing with Pandas 3, e.g. for results without a unit.

  • omnetpp.scave: Fixed convert_to_base_unit converting results with logarithmic units (e.g. dBm) point-wise, which gives wrong results for the mean and stddev columns. Such results are now left unchanged (#1514).

  • Fixed fields of statistics, histograms and vectors exposed as scalars (include_fields=True, also in the Analysis Tool) inheriting the unit of the containing item. Now count-like fields have no unit, and the start/end time of vectors is in seconds (related to #1513).

  • omnetpp.scave.vectorops: Fixed merge and aggregate failing (also in Analysis Tool charts) when the vectors differed in an attribute such as the title, and one of them had an empty value for it.

Analysis Tool:

  • Fixed chart pan/zoom with matplotlib 3.11 (#1519), and the 3dchart_itervars chart template with matplotlib 3.9 and later.

  • Updated Py4J to 0.10.9.9 and Pickle to 1.5.

NED Editor:

  • Added support for the clipChildren attribute of shape figures. Due to limitations of Draw2D, the clip region is approximated with its bounding rectangle, so clipping is exact only for unrotated rectangles without rounded corners.

  • Fixed several gaps and differences from Qtenv in the rendering of the graphical editor, such as panel figures (NED files containing them failed to open), the g (layout group) display string tag, some @figure transforms, and the is and i tags on the default icon. Also fixed submodules jumping away when moved or pinned.

Other IDE Components:

  • NED Documentation Generator: Projects can now be documented without their dependencies (e.g. Simu5G without INET), with links to the separately generated documentation of the referenced projects ("External documentation" option). References to types that are not documented are marked as coming from another project instead of becoming broken links.

  • NED Documentation Generator: Added an option to generate PNG images instead of SVG. The generator now asks for confirmation if the selected projects have NED errors. Fixed image generation errors not being reported (producing pages with missing diagrams), exporting NED type diagrams with transformed @figures into SVG, and the navigation tree jumping away when clicking through a list.

  • Ini File Editor: Runtime checks and diagnostic output options were moved to a new "Diagnostics" page. Added the unused-entry-check options, and content assist for the values of config-recording, output-vector-db-indexing and cmdenv-log-level.

  • Updated the bundled Eclipse platform to 2026-09.

Samples:

  • openstreetmap: The map is now clipped to the map area, so streets, buildings and cars no longer stick out of the background.

Install Guide:

  • The Python virtual environment is now set up using uv (pip remains an alternative).

Build:

  • setenv now activates the Python virtual environment as its first step; fixed the virtual environment not being activated on NixOS. On NixOS, the setenv environment is pinned to nixos-26.05 and no longer leaks host libraries into the shell.

  • Updated the bundled SQLite to 3.54.1, backward-cpp to 1.6 and nanobind to 3.1.0. Silenced compiler warnings about _XOPEN_SOURCE being redefined.

See ChangeLogs in individual folders for details.

Bugs fixed: https://github.com/omnetpp/omnetpp/issues?q=is%3Aissue+is%3Aclosed+milestone%3A6.5


What's New in OMNEST 6.4.0