The manifest builds Flectar Mail from the checked-out source without network access during compilation. Install the 25.08 Freedesktop SDK and Rust extension, then run ./scripts/build-flatpak.sh. The resulting standalone test bundle is target/flatpak/flectar-mail.flatpak.

The Flatpak-specific Cargo feature disables close-to-tray. Slint's current tray backend owns a legacy StatusNotifier D-Bus name outside the application ID, which Flathub rejects for new apps. Native packages retain tray support.

cargo-sources.json was generated from Cargo.lock with the official flatpak-cargo-generator.py at commit 1fc32195e3e60fe5c97f0af646dec7a99df5962b. Run the generator again whenever Cargo.lock changes. The release test suite rejects missing, extra, or stale crate archives and checksums.

This preview manifest uses the local checkout so the release workflow always packages the commit being tested. A future Flathub repository must replace that source with the checksum-pinned stable release archive. It must also build PDFium from source or disable PDF preview because Flathub does not accept this third-party prebuilt PDFium archive for an app submission.