Bug#1107768: unblock: dhcpcd/1:10.1.0-12
su 15.6.2025 klo 18.26 Michael Biebl (biebl@debian.org) kirjoitti:
>
> [network-manager maintainer speaking here]
>
> Am 14.06.25 um 06:52 schrieb Martin-Éric Racine:
>
> > [ Reason ]
> > As someone found out during the soft freeze, a daemonized dhcpcd competes with network-manager and other network configuration tools for control over the network interfaces and resolver.
> >
> > Back when I took over maintenance of the package, I ended up spliting the init.d script and systemd unit into a separate bin:dhcpcd package precisely to avoid this. Apparently, that wasn't enough. I therefore just added a "Conflicts: network-manager" to bin:dhcpcd to further drive the point that having two networking daemons on the same host is a bad idea. This is the only change.
> >
> > Meanwhile, bin:dhcpcd-base remains perfectly harmless on hosts running systemd-networkd or network-manager, since it doesn't come with startup scripts and is instead executed via ifupdown or some other network configuration framework as per administrator configuration.
> >
> > [ Impact ]
> > Without this fix, bug reports similar to #1107683 are likely to be filed after Trixie is released.
> >
> > [ Tests ]
> > None needed. It's only a dependency change (Conflicts: network-manager).
>
> In the past, network management systems did not declare conflicts
> against each other.
Indeed, but it if even an experienced Debian developer ended up filing
a bug wondering why 2 network configuration daemons compete for the
same interfaces, it strongly indicates a need for idiot-proofing
dependencies.
> If what you say is true, and dhcpcd interferes with networkd,
> NetworkManager, ifupdown and its variants, why was only a Conflicts
> against the network-manager added?
Because, as the bug report that caused this change showed, it's the
most obvious case. Ideally, I'd also have a Conflicts against
networkd, but it's not a separate package, and it needs to be
explicitly enabled, so we'll manage fine.
Please also note that the dhcpcd binary itself doesn't compete for
control of the interfaces and resolver; it's as passive as dhclient
was, hence why dhcpcd-base (it could just as easily been called
dhcpcd-bin) remains perfectly harmless even on a host that uses
networkd or network-manager. In the later case, IIRC, we even have a
netowrk-manager backend that can use the dhcpcd binary?
Btw, it's interesting that you phrased this as dhcpcd interfering with
others, and not the other way around. Biased, much?
Martin-Éric
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