Apt 2.0 introduced a new feature allowing to use smarter patterns when listing packages. This allows to list all obsolete packages using the specifier ?obsolete or the shorthand ~o.
$ apt list ?obsolete
It will list all locally installed packages and packages.
You can also list all packages not provided by Debian (it will also catch packages once provided by Debian but since then remove from the repositories):
$ apt list --installed "?not(?origin(debian))"
After migrating to PipeWire you would want to fully remove PulseAudio. The problem is that certain packages, for example libcanberra-pulse, depend on pulseaudio even though they would work just as well if pipewire-pulse is installed. There are several relevant bugs to solve this issue, but meanwhile we could use equivs to generate a fake package that provides pulseaudio.
Copy the following file locally as pulseaudio-fake:
Section: misc
Priority: optional
Standards-Version: 3.9.2
Package: pulseaudio-fake
Provides: pulseaudio
Description: Fake pulseaudio package to satisfy depdendencies.
This solves depdendencies for packages like libcanberra-pulse when actually using PipeWire instead of PulseAudio.
Build a package from it using equivs and install it:
$ equivs-build ./pulseaudio-fake
$ sudo apt install ./pulseaudio-fake_1.0_all.deb
Now you can safely remove pulseaudio.
This post outlines how I backported rtl8812au-dkms from Ubuntu Focal for Debian Buster and added support for the TP-Link Archer T4U v2 card to it. If you are only interested in the resulting .deb file skip to the end.
The TP-Link Archer T4U v2 is an AC1300 WiFi USB adapter. TP-Link provides drivers but they are built only for old kernel versions (<=3.19) and do not supoort DKMS, which makes upgrading a hassle.
Ubuntu provides the rtl8812au-dkms package which support the chipset in the Archer T4Uv2, but it doesn’t recognize the TP-Link product. So I set out to backport it to Debian Buster and make it support the Archer T4Uv2.
We start by fetching the rtl8812au source package from Ubuntu.
$ dget --allow-unauthenticated http://archive.ubuntu.com/ubuntu/pool/universe/r/rtl8812au/rtl8812au_4.3.8.12175.20140902+dfsg-0ubuntu12.dsc
$ cd rtl8812au-4.3.8.12175.20140902+dfsg/
$ sed -i s/dh-modaliases// debian/control
$ sed -i s/,modaliases// debian/rules
$ mk-build-deps ./debian/control --install --root-cmd sudo --remove
The sed lines remove reference to the dh-modaliases build dependency which Debian doesn’t have. I’m not really sure why they needed it for this package, but removing it didn’t hurt.
Next we add a new patch using quilt to support the Archer T4Uv2. We extract the 2357:010d USB vid:pid pair of the adapter using lsusb.
$ quilt push -a
$ quilt new add_archer_t4uv2.patch
$ quilt add os_dep/linux/usb_intf.c
$ vim os_dep/linux/usb_intf.c
The change we’ll be making to os_dep/linux/usb_intf.c is outlined by the following patch:
--- rtl8812au-4.3.8.12175.20140902+dfsg.orig/os_dep/linux/usb_intf.c
+++ rtl8812au-4.3.8.12175.20140902+dfsg/os_dep/linux/usb_intf.c
@@ -303,6 +303,7 @@ static struct usb_device_id rtw_usb_id_t
{USB_DEVICE(0x20f4, 0x805b),.driver_info = RTL8812}, /* TRENDnet - */
{USB_DEVICE(0x2357, 0x0101),.driver_info = RTL8812}, /* TP-Link - Archer T4U */
{USB_DEVICE(0x2357, 0x0103),.driver_info = RTL8812}, /* TP-Link - Archer T4UH */
+ {USB_DEVICE(0x2357, 0x010d),.driver_info = RTL8812}, /* TP-Link - Archer T4Uv2 */
{USB_DEVICE(0x0411, 0x025d),.driver_info = RTL8812}, /* Buffalo - WI-U3-866D */
#endif
Finish up adding the patch:
$ quilt header --dep3 -e
$ quilt refresh
$ quilt pop -a
And build the package:
$ DEBEMAIL="Guy Rutenberg <guyrutenberg@gmail.com>" debchange --bpo
$ debuild -us -uc
Now we can install the newly created deb package:
$ cd ../
$ sudo apt install ./rtl8812au-dkms_4.3.8.12175.20140902+dfsg-0ubuntu12~bpo10+1_all.deb
If you came here only for the actual binary package you can find it in my deb repository: https://guyrutenberg.com/debian/buster/
If you are building a package from source on Debian or Ubuntu, usually the first step is to install the build-dependencies of the package. This is usually done with one of two commands:
$ sudo apt-get build-dep PKGNAME
or
$ sudo aptitude build-dep PKGNAME
The problem is that there is no easy way to undo or revert the installation of the build dependencies. All the installed packages are marked as manually installed, so later one cannot simply expect to “autoremove” those packages. Webupd8 suggests clever one-liner that tries to parse the build dependencies out of apt-cache and mark them as automatically installed. However, as mentioned in the comments, it may be too liberal in marking packages as automatically installed, and hence remove too many packages.
The real solution is mk-build-deps. First you have to install it:
$ sudo apt install devscripts
Now, instead of using apt-get or aptitude directly to install the build-dependencies, use mk-build-deps.
$ mk-build-deps PKGNAME --install --root-cmd sudo --remove
mk-build-deps will create a new package, called PKGNAME-build-deps, which depends on all the build-dependencies of PKGNAME and then install it, therefore pulling all the build-dependencies and installing them as well. As those packages are now installed as dependencies they are marked as automatically installed. Once, you no longer need the build-dependencies, you can remove the package PKGNAME-build-deps, and apt will autoremove all the build-dependencies which are no longer necessary.