pidgin/nest

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6 days ago, Gary Kramlich
957ad9b1500d
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Testing Done:
Ran `hugo server` and verified everything was working.

Reviewed at https://reviews.imfreedom.org/r/1024/
---
title: "Pidgin3 Development Scripts"
date: 2021-06-09T01:26:16-05:00
---
## Introduction
Developing Pidgin 3 can be quite complicated and error prone. Compilation and
installation takes a long time and even running an additional instance can be
a painful as there are currently two command line arguments that need to be set
to make it work.
To make all of this work we use a number of scripts. In fact you may even have
seen some of them in use on [grim's stream](https://twitch.tv/rw_grim). But
there's one more piece to all of this and that is the installation prefix.
## Prefixes
All projects that use autotools, cmake, meson, qmake, etc have what we call
an installation prefix. It's what tells the build system where to install the
software. By default this is typically `/usr/local` which means your executables
will end up in `/usr/local/bin`, your libraries in `/usr/local/lib` and so on.
Using the default is usually fine if you're just running the software, but while
developing the need might arise for you to delete everything that's been
installed. While all of these build systems include an uninstall target, there
are times when you'll update your local copy and not realize that installed
files have been removed and they end up polluting your install prefix and can
cause bugs that are very difficult to debug because there are files that are
there that you're not expecting.
To avoid this or having to run the uninstall target before every update we make
it easy to delete everything by using a custom prefix. You're free to use
whatever prefix you like, but grim uses `~/l`. The `l` is just an abbreviation
of `local` and is less likely to be confused with `~/.local` which is something
[completely different](https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html).
Using a custom prefix also makes it very easy to make sure we're always building
our subprojects of GPlugin, libgnt, and Talkatu. This is important because at
the current stage of development these are being updated directly for Pidgin 3
and vice versa. This works because meson doesn't add the prefix to the
`PKG_CONFIG_PATH` environment variable so `pkg-config` is unable to find the
installed copies of our subprojects and thus always builds them.
To set the prefix we pass it as an argument to meson during initial
configuration via `meson --prefix=~/l build` or after the fact using
`meson configure --prefix=~/l` from an existing build directory.
## Scripts
Now that the prefix is setup we can start talking about the main developer
scripts. They are `dev-log-grep`, `dev-pidgin`, `local-pidgin`, and
`dev-pidgin-glade`.
* [dev-log-grep]({{< ref "#dev-log-grep" >}}) helps sort through the compiler
output as there are currently many deprecation warnings that we're slowing
churning through.
* [dev-pidgin]({{< ref "#dev-pidgin" >}}) and
[local-pidgin]({{< ref "#local-pidgin" >}}) are used to run Pidgin 3 from a
build directory and a local installation respectively.
* [dev-pidgin-glade]({{< ref "#dev-pidgin-glade" >}}) is used to create and
edit our user interface templates in Glade.
These scripts need to be available on your `PATH`. Typically people put these
in `~/bin` or `~/.local/bin` and will need to be added to your `PATH`
environment variable via your shell's initialization which is outside of the
scope of this document.
### dev-log-grep
`dev-log-grep` is a simple script that uses grep to ignore the deprecation
warnings from the compiler output. However, it was built to run after the build.
This works best when doing a clean build, that is running `ninja clean` before
running `ninja` but that isn't necessary. However, you need to slightly modify
your `ninja` command to make this work. The ninja command you need to use is
`ninja |& tee log`. This will run the build like normal, then you can use
`dev-log-grep` to see the warnings that we aren't ignoring.
The contents of `dev-log-grep` can be found below.
```
#!/bin/sh
grep -i warning log | grep -vi deprec | grep -vi "failed to parse" | grep -vi "bare structure or union" | grep -vi "callbacks cannot be return values" | grep -v "Unresolved type"
```
### dev-pidgin
The `dev-pidgin` script is used to run Pidgin from your build directory. This is
useful if you're just testing something in libpurple or Pidgin directly, but if
you're working on plugins you'll need to use `local-pidgin` which is explained
later.
The contents of `dev-pidgin` are below. You can tweak them as necessary, but
we'll walk through what it does.
```sh
#!/bin/sh -e
TOOL="gdb --args"
#TOOL="valgrind --leak-check=full --suppressions=/usr/share/glib-2.0/valgrind/glib.supp --suppressions=/usr/share/gtk-3.0/valgrind/gtk.supp"
export LD_LIBRARY_PATH=libpurple/:pidgin/
${TOOL} pidgin/pidgin3 \
--gapplication-app-id=im.pidgin.dev \
--config ~/.pidgin3-dev \
--debug \
${@}
```
The first line sets up our shell interpreter and tells it to exit on the first
error it encounters. Lines 3 and 4 are an optional prefix we can use to run
Pidgin 3 in either gdb or valgrind.
We use gdb for debugging and valgrind for finding memory leaks and other memory
errors. The paths for the valgrind suppressions are distribution dependent and
may not be available on distributions. The ones listed here are from a Debian
system. Only one of these can be used at a time so just make sure to uncomment
the one you would like to use.
Next we update `LD_LIBRARY_PATH` to tell the dynamic linker where to find the
libraries that are part of our build. If you're on macOS you'll need to set
`DYLIB_LIBRARY_PATH` instead.
Finally we have the command that will actually run Pidgin 3. It uses the prefix
variable if defined, then specifies the `pidgin3` executable to run. The
`--gapplication-app-id` argument is used to uniquely identify this instance of
Pidgin 3. This identifier is used to allow only one instance matching this
identifier to run at a time.
The `--config` argument specifies where Pidgin 3 will store its configuration
data. Next the `--debug` argument tells Pidgin to output all of the debug
statements to the console. Finally `${@}` will pass any arguments that were
passed to `dev-pidgin` to be passed to the `pidgin3` executable.
### local-pidgin
`local-pidgin` is nearly identical to `dev-pidgin` so we won't go into much
depth as most of it is already covered above. The point of `local-pidgin` is
to be able to run `pidgin3` from an installed prefix that is not `/usr` or
`/usr/local`. In the example below we have Pidgin 3 installed with a prefix of
`~/l` like we discussed earlier.
```
#!/bin/sh -e
TOOL="gdb --args"
#TOOL="valgrind --leak-check=full --suppressions=/usr/share/glib-2.0/valgrind/glib.supp --suppressions=/usr/share/gtk-3.0/valgrind/gtk.supp"
export LD_LIBRARY_PATH=~/l/lib/x86_64-linux-gnu
${TOOL} ~/l/bin/pidgin3 \
--gapplication-app-id=im.pidgin.local \
--config ~/.pidgin3-local \
--debug \
${@}
```
Since this is for the installed version of Pidgin 3 we just need to point to
everything for that installation. That means updating `LD_LIBARY_PATH`, or
`DYLIB_LIBRARY_PATH` if you're on macOS, as well as changing the path to the
`pidgin3` executable.
Finally we set a separate application id as well as configuration directory.
These do not need to be different than the ones from `dev-pidgin` but if you
want to run both instances for testing things this makes it easier.
### dev-pidgin-glade
`dev-pidgin-glade` is the last of our development scripts. Its purpose is to
allow developers to create and modify glade templates for Pidgin 3. This works
by the use of a Glade catalog for the Pidgin widgets. However, in this intro
we're just going to cover how to edit templates for Pidgin 3 but not adding
new widgets to the catalog.
This script is designed to be run from a Pidgin 3 build directory after Pidgin 3
has been built. This is necessary so that Glade can actually load the required
libraries and catalogs.
```
#!/bin/sh
export LD_LIBRARY_PATH=pidgin/:libpurple/:subprojects/talkatu/talkatu:subprojects/gplugin/gplugin-gtk/
export GLADE_CATALOG_SEARCH_PATH=pidgin/glade:subprojects/gplugin/gplugin-gtk:subprojects/talkatu/talkatu
glade ${@}
```
Like the other script here, this one sets up `LD_LIBRARY_PATH` to point to the
libraries in the build directory. Remember if you're on macOS this needs to be
`DYLIB_LIBRARY_PATH`.
Next, we tell Glade where to find the catalogs for Pidgin, GPluginGtk, and
Talkatu all of which we are building and depend on.
With everything set up we can finally run Glade passing along any arguments that
were passed to our script.
---
We hope you all found this information useful and we will keep this post updated
in the future.