Bug#880802: No documented way to pass a command into cowbuilder execute

[Russ Allbery]

Package: cowbuilder
Version: 0.85
Severity: normal

The cowbuilder man page claims to support an execute operation, but I
cannot figure out how to pass in the command and there's no example.
I tried all of:

$ cowbuilder execute apt update --basepath /var/cache/pbuilder/base-experimental.cow
$ cowbuilder --execute --basepath /var/cache/pbuilder/base-experimental.cow apt update
$ cowbuilder --execute 'apt update' --basepath /var/cache/pbuilder/base-experimental.cow
$ cowbuilder --execute --basepath /var/cache/pbuilder/base-experimental.cow
$ cowbuilder --execute --basepath /var/cache/pbuilder/base-experimental.cow 'apt update'
$ cowbuilder --execute --basepath /var/cache/pbuilder/base-experimental.cow -- apt update

and none of them worked.  Could you let me know what I'm missing and add
an example or some more documentation to the cowbuilder man page?

-- System Information:
Debian Release: buster/sid
  APT prefers unstable
  APT policy: (990, 'unstable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.13.0-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages cowbuilder depends on:
ii  cowdancer    0.85
ii  libc6        2.24-17
ii  libncurses5  6.0+20170902-1
ii  libtinfo5    6.0+20170902-1
ii  pbuilder     0.229

cowbuilder recommends no packages.

cowbuilder suggests no packages.

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