Linux system requirements¶

The Linux binary is statically linked against most of its C++ runtime stack, so the dependency surface visible to the user is small. On a vanilla server install you typically need to add a handful of packages to make the analyser fully functional.

Required at runtime¶

These are linked dynamically and must be present:

libtinfo5: Terminfo database, used for colour/cursor detection. On distributions that have moved to libtinfo6 (Ubuntu 24.04+), the libtinfo5 compatibility package is available from the universe repository.
openssl: Runtime libcrypto/libssl for the bundled cmark / fetch helpers. Both 1.1.x and 3.x work.
libstdc++: Comes with system gcc; available on every distribution out of the box.

Optional but strongly recommended¶

gcc (any modern version): Necessary for toolchain auto-detection. Without a system compiler, the analyser probes through --compiler-path. Then you register each cross toolchain yourself.
clang: The same role as gcc. The analyser uses either compiler. Both compilers together give more exact diagnostics for the Clang extensions.
graphviz (the dot program): Necessary for --dep-graph-out-png. Without graphviz, the analyser writes the .dot source and omits the PNG step.
go: Required to detect Go targets. The Go detector runs go tool dist list to enumerate the supported triples.

Tested distributions¶

Distribution	`x86_64`
Ubuntu 22.04 LTS	`+ (T)`
Ubuntu 24.04 LTS	`+`
Debian 12	`+`
Fedora 39 / 40	`+`
RHEL 9 / AlmaLinux 9	`+`
Alpine 3.20	`+` (musl, see below)

(T) marks the distribution used in the Jenkins build/test matrix.

Installation hints¶

Debian / Ubuntu:

sudo apt-get update
sudo apt-get install -y libtinfo5 openssl gcc graphviz

(libtinfo5 lives in the universe component on Ubuntu. Run sudo add-apt-repository universe first to enable that component.)

Fedora / RHEL family:

sudo dnf install -y ncurses-compat-libs openssl gcc graphviz

Alpine (musl libc):

apk add ncurses-libs openssl gcc graphviz

The musl build of the Linux tarball ships with no glibc dependency. Static linking covers the C++ side; libtinfo5 is only required if you do not pass --no-color.

Headless / minimal containers¶

For CI containers and minimal scratch images:

Skip gcc if you only ever pass --compiler-path for an explicit cross toolchain.
Skip graphviz if you never use the dependency-graph output.
Set VISAO_DISABLE_COLORS=y (or pass --no-color). Log capture in CI reads plain text, and this setting also removes the libtinfo5 dependency.

A minimal Alpine container that runs visao --no-color --language c <file> typically needs only musl, libstdc++, ncurses-libs (for terminfo lookup at startup) and openssl-libs. The bundled dockerfile/ubuntu/Dockerfile in the release tarball is the canonical reference; see Run through Docker.

Permissions¶

The analyser only reads. No setuid / setcap / capability changes are needed. The toolchain probe cache lives under the user’s config dir. A system service needs write access to ~/.config/visao/. You can also set $XDG_CONFIG_HOME to a service-owned path.