Rust build failed: GTK/GDK system library is missing

The Rust dependency gdk-sys v0.18.2 could not be built (it compiles or links a C library). The full output is in the deploy log.

Seen2 times
WhereRust

Why it happens

The Rust dependency gdk-sys v0.18.2 needs the native GTK/GDK 3 library during compilation. The build environment could not find gdk-3.0.pc through pkg-config, and PKG_CONFIG_PATH was not set. This is a missing system dependency, not a Cargo registry or source checkout failure.

What the log looks like

Deploy log
Compiling gdk-sys v0.18.2error: failed to run custom build command for `gdk-sys v0.18.2`pkg-config exited with status code 1The system library `gdk-3.0` required by crate `gdk-sys` was not found.The file `gdk-3.0.pc` needs to be installed and the PKG_CONFIG_PATH environment variable must contain its parent directory.The PKG_CONFIG_PATH environment variable is not set.

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