[Documentation] Missing libevent-dev in Linux prerequisites causes ot-commissioner linker failure.

[Saravana-kr22]

Documentation issues

PR #43029 ("Add Commissioning over Thread Meshcop for python controller") was merged on 2026-02-13. This PR introduced a new dependency on the OpenThread Commissioner library (ot-commissioner) for Thread MeshCoP commissioning support.

The ot-commissioner build target (in third_party/ot-commissioner/BUILD.gn) links against libevent system libraries.

These are provided by the libevent-dev system package on Debian/Ubuntu. However, libevent-dev is not listed in the Linux prerequisites section of docs/guides/BUILDING.md.

The Thread MeshCoP feature is enabled by default on Linux when matter_enable_recommended is true.

The apt-get install command in the Installing prerequisites on Linux section of BUILDING.md does not include libevent-dev:

sudo apt-get install git gcc g++ pkg-config cmake curl libssl-dev libdbus-1-dev \
     libglib2.0-dev libavahi-client-dev ninja-build python3-venv python3-dev \
     python3-pip unzip libgirepository1.0-dev libcairo2-dev libreadline-dev \
     default-jre

Impact

• Any developer building chip-tool, the Python controller, or other controller targets on a fresh Linux environment will hit a linker failure because libevent_core and libevent_pthreads cannot be found.
• This is related to existing issue #43132 which also reports chip-tool build failures after this PR merge.
• The Docker images and CI scripts already include libevent-dev (e.g., in integrations/docker/images/base/chip-build/Dockerfile and scripts/setup/linux/install_packages.sh), so CI passes, but local developer builds fail.

Fix Needed

• Add libevent-dev to the apt-get install command in docs/guides/BUILDING.md under "Installing prerequisites on Linux".

[cjandhyala]

@Saravana-kr22 Could you pls get a PR for the same ?

[cecille]

PR is now merged, closing this issue.