Problem

An embedded Linux device with a readonly mount of path /opt means opkg fails Could not create lock file /opt/tmp/opkg.lock. The opkg installer should allow a different lockfile location, .e.g. --lock path/opkg.lock

Reproduction

Given any system with readonly /opt path.

1. cd /tmp
2. Download the opkg file.
3. Download the opkg.conf file.
4. Change opkg.conf file from

src/gz entware http://bin.entware.net/armv7sf-k3.2
dest root /
dest ram /opt/tmp
lists_dir ext /opt/var/opkg-lists
option tmp_dir /opt/tmp
arch all 100
arch armv7-3.2 160

to a writeable location (any writable path will do; just prepend /tmp)

src/gz entware http://bin.entware.net/armv7sf-k3.2
dest root /
dest ram /tmp/opt/tmp
lists_dir ext /tmp/opt/var/opkg-lists
option tmp_dir /tmp/opt/tmp
arch all 100
arch armv7-3.2 160

5. run opkg

$ /tmp/opkg --conf /tmp/opkg.conf -V3 -d /tmp/ -t /tmp/ update
opkg_conf_parse_file: Loading conf file /tmp/opkg.conf.
opkg_conf_parse_file: Supported arch all priority (100)
opkg_conf_parse_file: Supported arch armv7-3.2 priority (160)
Collected errors:
 * opkg_conf_set_option: Duplicate option tmp_dir, using first seen value "/tmp/".
 * opkg_conf_load: Could not create lock file /opt/tmp/opkg.lock: No such file or directory.

The culprit message is Could not create lock file /opt/tmp/opkg.lock: No such file or directory.
On my system, the path /opt is readonly (because the mount root / is readonly). The / is of type squashfs and so cannot be remounted as read-write (mount -o remount,rw / has no affect).

Solution

The opkg should have an option to specify the lockfile path.

$ /tmp/opkg --lock /tmp/opkg.lock

The opkg.conf should also allow specifying the lockfile path.

Environment

• Entware feed: armv7sf-k3.2
• Firmware version DDWRT latest