Fedora Linux Knowledge Patch

Claude's baseline knowledge covers Fedora Linux through Fedora 40. This skill provides breaking changes from Fedora 41–44 (2024-10 through 2026-04) that affect scripts, automation, Dockerfiles, and system administration.

Breaking Changes Quick Reference

Version	Change	Impact	Details
F41+	DNF5 replaces DNF4	Commands renamed/restructured; config paths changed	dnf5
F41	Redis → Valkey	Package/binary/service names changed	package-changes
F41	NetworkManager drops ifcfg	/etc/sysconfig/network-scripts/ removed	system-changes
F41	OpenSSL distrusts SHA-1	TLS to SHA-1 cert servers fails	crypto-changes
F41	OpenSSL ENGINE API deprecated	Must use provider API instead	crypto-changes
F41	Python 2.7 removed	python2/python2.7 packages gone	package-changes
F41	nftables default for Podman/libvirt	iptables rules don't show container/VM rules	system-changes
F42	/usr/sbin → /usr/bin	Sbin removed from $PATH; all binaries in /usr/bin	system-changes
F42	fips-mode-setup removed	Use fips=1 kernel arg instead	crypto-changes
F42	setup.py install removed	Use pip install . or pyproject.toml builds	package-changes
F42	Anaconda WebUI + VNC→RDP	inst.vnc replaced by inst.rdp	system-changes
F43	RPM 6.0	Enforced signatures, v6 format, new signing config	package-changes
F43	lastlog → lastlog2	/var/log/lastlog gone, sqlite-based replacement	system-changes
F43	Wayland-only GNOME	X11 session packages removed	system-changes
F44	CA cert.pem files dropped	Hardcoded CA bundle paths break	crypto-changes
F44	CMake 4.0	cmake_minimum_required < 3.5 fails	package-changes
F44	Podman 6	BoltDB removed, nftables only, config rework	package-changes

DNF5 Quick Reference (Fedora 41+)

dnf is now DNF5 (C++ rewrite). Scripts using DNF4 syntax will break.

Most common command changes:

DNF4	DNF5
dnf history <id>	dnf history info <id>
dnf updateinfo	dnf advisory summary
dnf groupinstall <grp>	dnf group install <grp>
dnf config-manager --add-repo URL	dnf config-manager addrepo --from-repofile=URL
dnf config-manager --save --setopt=..	dnf config-manager setopt key=value
dnf shell	dnf do install pkg1 remove pkg2
dnf mark install pkg	dnf mark user pkg
dnf mark remove pkg	dnf mark dependency pkg
dnf download --source pkg	dnf download --srpm pkg
dnf rq --resolve --requires pkg	dnf rq --providers-of=requires pkg

Dropped options: -4/-6 (use ip_resolve config), --verbose, --downloaddir (use --destdir), --skip-broken on upgrade (use --no-best).

Config changes: Cache dir is /var/cache/libdnf5 (root) / ~/.cache/libdnf5 (user). best=true by default. Timer: dnf5-makecache.timer. Auto-updates: dnf5-automatic.timer. strict option split into skip_broken and skip_unavailable.

See references/dnf5.md for full details.

Redis → Valkey (Fedora 41+)

Redis removed due to license change (BSD → RSALv2/SSPL). Valkey 7.2 is the wire-compatible BSD-licensed replacement.

# Migration on existing systems:
dnf install valkey-compat-redis --allowerasing

# Fresh install:
dnf install valkey

Redis (old)	Valkey (new)
redis-server / redis-cli	valkey-server / valkey-cli
systemctl start redis	systemctl start valkey
/etc/redis/redis.conf	/etc/valkey/valkey.conf
/var/lib/redis/	/var/lib/valkey/

Data files (RDB/AOF) are compatible. Port 6379 unchanged. The valkey-compat package provides redis.service → valkey.service systemd alias.

Caution: Check shutdown-on-sigterm setting — if set to nosave or force, data may be lost during migration restart.

Crypto & TLS Changes Summary

• F41: OpenSSL distrusts SHA-1. Revert: update-crypto-policies --set FEDORA40. Per-process: runcp FEDORA40 <command>.
• F41: ENGINE API disabled. Use pkcs11-provider instead of engine_pkcs11.
• F42: fips-mode-setup removed. Enable FIPS at install with fips=1 kernel arg. Post-install workaround: grubby --update-kernel=ALL --args="fips=1".
• F44: /etc/pki/tls/cert.pem and CA bundle files removed. Use /etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem instead.

See references/crypto-changes.md for full details.

nftables Default (Fedora 41)

Both Podman/Netavark and libvirt switch to nftables. iptables -L shows nothing for container/VM rules.

nft list ruleset   # see all firewall rules including containers/VMs

Docker incompatibility: Docker sets iptables FORWARD policy to DENY, which blocks nftables rules in libvirt's separate table. Workaround:

# /etc/libvirt/network.conf
firewall_backend = "iptables"

Then: systemctl restart virtnetworkd

Anaconda Installer Changes (Fedora 42+)

• F42: New WebUI installer (PatternFly-based wizard) replaces GTK for Workstation. Guided partitioning with dual-boot support.
• F42: VNC removed from installer. Use RDP: inst.rdp and inst.rdp.password=<pass> boot options.
• F43: WebUI becomes default for all Spins and KDE edition.

Other Breaking Changes

• F41: Python 2.7 fully removed. dnf install python2 fails.
• F42: /usr/sbin → symlink to /usr/bin. /usr/sbin removed from $PATH. Use /usr/bin/ in new scripts.
• F42: Setuptools 74+ removes setup.py install. Use pip install ..
• F43: RPM 6.0. Defaults to enforced signature checking and v6 format. Signing: use %_openpgp_sign_id (not custom %__gpg_sign_cmd). v3 packages can no longer be installed. MD5/SHA1 digests disabled. Control format: %_rpmformat 4 to keep v4.
• F43: lastlog → lastlog2 (sqlite-based, from util-linux). Automatic migration on upgrade.
• F43: Wayland-only GNOME. gnome-session-xsession and gnome-classic-session-xsession removed. XWayland still available for X11 apps.
• F44: CMake 4.0. cmake_minimum_required < 3.5 fails. Quick fix: -DCMAKE_POLICY_VERSION_MINIMUM=3.5. The %cmake RPM macro now uses ninja instead of make.
• F44: Podman 6. Removes BoltDB backend (must upgrade to Podman 5.8 first and reboot for SQLite migration), slirp4netns, cgroups v1. Netavark nftables-only. Config split into client/server files.

Software Versions (Fedora 44)

Python 3.14, Ruby 4.0, Node.js 24, Go 1.26, GCC 16.1, glibc 2.43, LLVM 22, Rust 1.86, MariaDB 11.8, PostgreSQL 18, Valkey 8.1, Ansible 13 (core 2.20), CMake 4.0, RPM 6.0, Podman 6, Helm 4, kernel 6.19, GNOME 50, KDE Plasma 6.6.

Reference Files

File	Contents
dnf5.md	DNF5 command migration, config changes, dropped options
system-changes.md	sbin/bin merge, NetworkManager, nftables, lastlog2, Anaconda, Wayland
crypto-changes.md	SHA-1 distrust, ENGINE API removal, FIPS, CA cert paths
package-changes.md	Redis→Valkey, Python 2 removal, setuptools, RPM 6.0, CMake 4.0, Podman 6