GENERATE-PACKAGE-NOTES(1)

📦 version 0.6, in ubuntu jammy

✨ GENERATE-PACKAGE-NOTES ✨

okay bestie, welcome to generate-package-notes from the General Commands Manual, and let me tell you, she's giving quiet genius 💅

🌸 SYNOPSIS 🌸

generate-package-notes [OPTION...]

💖 DESCRIPTION 💖

so here's the tea. ELF binaries get stamped with a unique, build-time generated hex string identifier called build-id, and that lil cutie gets embedded as an ELF note called .note.gnu.build-id. most of the time that's enough to link a stripped binary back up with its debugging info. like, it's used to dynamically fetch DWARF symbols from a debuginfo server, or to go ask the local package manager for the package metadata, or, again, the DWARF symbols or program sources. iconic behavior, honestly 🎀

but — and this is the plot twist — using build-id like that requires either local metadata (usually set up by the package manager) or access to a remote server over the network. and both of those might be unavailable or forbidden. 😭

so yeah, it becomes desirable to add extra metadata to a binary at build time, so that systemd-coredump(8) and other services analyzing core files can extract said metadata simply from the core file itself, with no external dependencies. no cap. the metadata is embedded in a single ELF header section, in a key-value JSON format. 🦋

the metadata format is intentionally left open so vendors can add their own info. a set of well-known keys is defined in the document Package Metadata for Core Files, and hopefully shared among all vendors. bestie teamwork fr fr.

generate-package-notes generates a linker script on standard output, which you can then use at build time via:

LDFLAGS="-Wl,-dT,/path/to/generated/script"

to include the note in the binary. and if a Debian package is built using the dh(1) sequencer, the generation can be partly automated using dh_package_notes(1). slay 🫶

🎀 OPTIONS 🎀

  • --package-type=TYPE — sets the key type to TYPE. defaults to package, but for Debian packages it should be set to deb.
  • --package-name=NAME — sets the key name to NAME. defaults to the empty string, but for Debian packages it should be set to the name of the binary package containing the binary.
  • --package-version=VERSION — sets the key version to VERSION. defaults to the empty string, but for Debian packages it should be set to the Debian version of the binary package containing the binary.
  • --package-architecture=ARCHITECTURE — sets the key architecture to ARCHITECTURE. defaults to the empty string, but for Debian packages it should be set to the Debian architecture identifier of the binary.
  • --root=PATH — when reading files, for example /usr/lib/system-release-cpe and /usr/lib/os-release, open them relatively to the specified directory.
  • --cpe=CPE — sets the key osCpe to CPE. if the special value auto is passed, then the content of the /usr/lib/system-release-cpe file, or the value of CPE_NAME from os-release if the former was not found, will be used. ✨
  • --rpm=PACKAGE-VERSION — sets the keys type to rpm, name to PACKAGE, and version to VERSION. overrides --package-type, --package-name, --package-architecture, and --package-version. she said "my way or the highway" 💀
  • --debug-info-url=URL — sets the key debugInfoUrl to URL. by default this key is omitted, but for Debian packages it should be set to the official Debian debuginfod server address https://debuginfod.debian.org/.
  • -h, --help — show a short help message and exit. the classic. the icon. 👑

🌈 SEE ALSO 🌈

and that's the whole page, bestie!! 🍓 this came to you straight from the General Commands Manual, dated May 2021 — so if you were wondering when this baddie was born, now you know. go generate some notes, drink water, and remember: the vibe check always passes when your metadata is embedded directly in the core file. 💜✨ mwah.

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