Qt - Revision history

Aura: Added nix lang on some code hightlight

2026-05-11T18:01:11Z

Added nix lang on some code hightlight

← Older revision		Revision as of 18:01, 11 May 2026
Line 13:		Line 13:
	For using direnv, create a '''shell.nix''' file in the root of your project and paste these lines into it:		For using direnv, create a '''shell.nix''' file in the root of your project and paste these lines into it:

	<~~syntaxHighlight~~ lang=nix>		<syntaxhighlight lang="nix"># shell.nix
	# shell.nix
	{ pkgs ? import <nixpkgs> {} }:		{ pkgs ? import <nixpkgs> {} }:
	pkgs.mkShell {		pkgs.mkShell {
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	pkgs.qtcreator		pkgs.qtcreator
	];		];
	}		}</syntaxhighlight>
	</~~syntaxHighlight~~>

	Also, create '''.envrc''' file and paste: <code>use_nix</code> into it.		Also, create '''.envrc''' file and paste: <code>use_nix</code> into it.
Line 30:		Line 28:
	If fetching the entirety of <code>pkgs.qt6.full</code> is not appealing and you know which parts of Qt you need, your first instinct might be adding something like <code>pkgs.qt6.qtdeclarative</code> for creating QML-based Qt programs to <code>buildInputs</code>, '''however''' that will not work and you will get compile errors for missing libraries. <code>pkgs.qt6.full</code> is actually [https://github.com/NixOS/nixpkgs/blob/nixos-24.11/pkgs/development/libraries/qt-6/default.nix#L94-L144 creating an environment that contains all Qt libraries] that allows <code>qmake</code> and tools to find those libraries, so you must do the same and <code>pkgs.qt6.env</code> will help make one. For example:		If fetching the entirety of <code>pkgs.qt6.full</code> is not appealing and you know which parts of Qt you need, your first instinct might be adding something like <code>pkgs.qt6.qtdeclarative</code> for creating QML-based Qt programs to <code>buildInputs</code>, '''however''' that will not work and you will get compile errors for missing libraries. <code>pkgs.qt6.full</code> is actually [https://github.com/NixOS/nixpkgs/blob/nixos-24.11/pkgs/development/libraries/qt-6/default.nix#L94-L144 creating an environment that contains all Qt libraries] that allows <code>qmake</code> and tools to find those libraries, so you must do the same and <code>pkgs.qt6.env</code> will help make one. For example:

	<syntaxhighlight lang="nix">		<syntaxhighlight lang="nix"># shell.nix
	# shell.nix
	{ pkgs ? import <nixpkgs> {} }:		{ pkgs ? import <nixpkgs> {} }:
	let		let
Line 48:		Line 45:
	pkgs.qtcreator		pkgs.qtcreator
	];		];
	}		}</syntaxhighlight>
	</syntaxhighlight>

	== Packaging ==		== Packaging ==
Line 138:		Line 134:

	For actual python applications, you may also use something like that (to test) :		For actual python applications, you may also use something like that (to test) :
	<syntaxHighlight>		<syntaxHighlight lang=nix>
	python3.pkgs.buildPythonApplication {		python3.pkgs.buildPythonApplication {
	pname = "blabla";		pname = "blabla";

Phobos: Updated grammar

2026-05-02T18:27:49Z

Updated grammar

← Older revision		Revision as of 18:27, 2 May 2026
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	{{warning\|With the deprecation of <code>qt5.full</code> & <code>qt6.full</code>, for 25.11 and up (see [https://github.com/NixOS/nixpkgs/blob/32b61ba4d9088ef926dd27065daad604ca6b58aa/pkgs/development/libraries/qt-6/default.nix#L152 change]) this recommendation is outdated. For now please primarily refer to the [[#Explicit Dependencies\|Explicit Dependencies]] Section below.}}		{{warning\|With the deprecation of <code>qt5.full</code> & <code>qt6.full</code>, for 25.11 and up (see [https://github.com/NixOS/nixpkgs/blob/32b61ba4d9088ef926dd27065daad604ca6b58aa/pkgs/development/libraries/qt-6/default.nix#L152 change]) this recommendation is outdated. For now please primarily refer to the [[#Explicit Dependencies\|Explicit Dependencies]] Section below.}}

	~~If you want to~~ develop qt applications in ~~nixos~~ you ~~have to~~ use nix-shell or direnv.		To develop Qt applications in NixOS you may use nix-shell or direnv.
	For using nix-shell just run this command in the terminal:		For using nix-shell just run this command in the terminal:

Line 24:		Line 24:
	</syntaxHighlight>		</syntaxHighlight>

	Also create '''.envrc''' file and paste: <code>use_nix</code> into it.		Also, create '''.envrc''' file and paste: <code>use_nix</code> into it.

	~~Happy qt coding :)~~

	=== Explicit Dependencies ===		=== Explicit Dependencies ===

	~~However if~~ fetching the entirety of <code>pkgs.qt6.full</code> is not appealing and you know which parts of Qt you need, your first instinct might be adding something like <code>pkgs.qt6.qtdeclarative</code> for creating QML-based Qt programs to <code>buildInputs</code>, '''however''' that will not work and you will get compile errors for missing libraries. <code>pkgs.qt6.full</code> is actually [https://github.com/NixOS/nixpkgs/blob/nixos-24.11/pkgs/development/libraries/qt-6/default.nix#L94-L144 creating an environment that contains all Qt libraries] that allows <code>qmake</code> and tools to find those libraries, so you must do the same and <code>pkgs.qt6.env</code> will help make one. For example:		If fetching the entirety of <code>pkgs.qt6.full</code> is not appealing and you know which parts of Qt you need, your first instinct might be adding something like <code>pkgs.qt6.qtdeclarative</code> for creating QML-based Qt programs to <code>buildInputs</code>, '''however''' that will not work and you will get compile errors for missing libraries. <code>pkgs.qt6.full</code> is actually [https://github.com/NixOS/nixpkgs/blob/nixos-24.11/pkgs/development/libraries/qt-6/default.nix#L94-L144 creating an environment that contains all Qt libraries] that allows <code>qmake</code> and tools to find those libraries, so you must do the same and <code>pkgs.qt6.env</code> will help make one. For example:

	<syntaxhighlight lang="nix">		<syntaxhighlight lang="nix">

Smudgebun: Added a warning for the deprecated Qt section

2026-03-13T09:47:57Z

Added a warning for the deprecated Qt section

← Older revision		Revision as of 09:47, 13 March 2026
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	== Development ==		== Development ==
			{{warning\|With the deprecation of <code>qt5.full</code> & <code>qt6.full</code>, for 25.11 and up (see [https://github.com/NixOS/nixpkgs/blob/32b61ba4d9088ef926dd27065daad604ca6b58aa/pkgs/development/libraries/qt-6/default.nix#L152 change]) this recommendation is outdated. For now please primarily refer to the [[#Explicit Dependencies\|Explicit Dependencies]] Section below.}}

	If you want to develop qt applications in nixos you have to use nix-shell or direnv.		If you want to develop qt applications in nixos you have to use nix-shell or direnv.
	For using nix-shell just run this command in the terminal:		For using nix-shell just run this command in the terminal:

Sandro: /* Troubleshooting */

2025-11-08T04:41:30Z

Troubleshooting

← Older revision		Revision as of 04:41, 8 November 2025
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	=== This application failed to start because it could not find or load the Qt platform plugin ??? in "" ===		=== This application failed to start because it could not find or load the Qt platform plugin ??? in "" ===
	~~==== qt5 ====~~
	{{warning\|This recommendation is deprecated for 19.09 and up, see {{issue\|65399}}. Failing packages should be updated to use <code>wrapQtAppsHook</code>.}}		{{warning\|This recommendation is deprecated for 19.09 and up, see {{issue\|65399}}. Failing packages should be updated to use <code>wrapQtAppsHook</code>.}}

	Qt5 seems (?) to look for plugins in the <code>PATH</code>. This will fail from a systemd user unit for example, because their path is nearly empty by default. As an example, here is a workaround to have <code>usbguard-applet</code> launched from a systemd user unit:
	~~{{File\|/etc/nixos/configuration.nix\|nix\|<nowiki>~~
	~~systemd.user.services.usbguard-applet = {~~
	~~description = "USBGuard applet";~~
	~~partOf = [ "graphical-session.target" ];~~
	~~wantedBy = [ "graphical-session.target" ];~~
	~~path = [ "/run/current-system/sw/" ]; ### Fix empty PATH to find qt plugins~~
	~~serviceConfig = {~~
	~~ExecStart = "${pkgs.usbguard}/bin/usbguard-applet-qt";~~
	};
	};
	~~</nowiki>}}~~

	~~==== qt.qpa.plugin: Could not find the Qt platform plugin "xcb" in "" ====~~
	~~Here is a concrete example:~~

	<pre>		<pre>
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	The package will need to be fixed to use [the new https://github.com/NixOS/nixpkgs/issues/65399 <code>wrapQtAppsHook</code>]. The hook wraps every qt application with adding <code>QT_PLUGIN_PATH</code> and <code>XDG_DATA_DIRS</code> as well as <code>XDG_CONFIG_DIRS</code>.See [https://github.com/NixOS/nixpkgs/blob/nixos-19.09/pkgs/development/libraries/qt-5/hooks/wrap-qt-apps-hook.sh wrap-qt-apps-hook.sh in nixpkgs]		The package will need to be fixed to use [the new https://github.com/NixOS/nixpkgs/issues/65399 <code>wrapQtAppsHook</code>]. The hook wraps every qt application with adding <code>QT_PLUGIN_PATH</code> and <code>XDG_DATA_DIRS</code> as well as <code>XDG_CONFIG_DIRS</code>.See [https://github.com/NixOS/nixpkgs/blob/nixos-19.09/pkgs/development/libraries/qt-5/hooks/wrap-qt-apps-hook.sh wrap-qt-apps-hook.sh in nixpkgs]

	==== Debugging methods ====		=== Debugging methods ===
	As a general rule, exporting <code>QT_DEBUG_PLUGINS=1</code> make qt print where it looks for plugins.		As a general rule, exporting <code>QT_DEBUG_PLUGINS=1</code> make qt print where it looks for plugins.

	If a plugin exists in a directory but is ignored with a message like <code>QLibraryPrivate::loadPlugin failed on "/nix/store/...-teamspeak-client-3.1.6/lib/teamspeak/platforms/libqxcb.so" : "Cannot load library /nix/store/...-client-3.1.6/lib/teamspeak/platforms/libqxcb.so: "</code> it can be that the library cannot be <code>dlopen()</code>ed because of dependencies/rpath issues and needs <code>patchelf</code>ing. Exporting <code>LD_DEBUG=libs</code> may prove helpful in this scenario.		If a plugin exists in a directory but is ignored with a message like <code>QLibraryPrivate::loadPlugin failed on "/nix/store/...-teamspeak-client-3.1.6/lib/teamspeak/platforms/libqxcb.so" : "Cannot load library /nix/store/...-client-3.1.6/lib/teamspeak/platforms/libqxcb.so: "</code> it can be that the library cannot be <code>dlopen()</code>ed because of dependencies/rpath issues and needs <code>patchelf</code>ing. Exporting <code>LD_DEBUG=libs</code> may prove helpful in this scenario.

Sandro: /* Cannot mix incompatible Qt library (version 0x_) with this library (version 0x_) */

2025-11-08T04:39:15Z

Cannot mix incompatible Qt library (version 0x_____) with this library (version 0x_____)

← Older revision		Revision as of 04:39, 8 November 2025
Line 192:		Line 192:

	== Troubleshooting ==		== Troubleshooting ==

	~~=== Cannot mix incompatible Qt library (version 0x_____) with this library (version 0x_____) ===~~

	~~This is a known issue, see {{issue\|30551}} for the current status.~~

	~~Starting with the 19.09 release, the issue should be fixed by {{pull\|65526}}~~

	=== This application failed to start because it could not find or load the Qt platform plugin ??? in "" ===		=== This application failed to start because it could not find or load the Qt platform plugin ??? in "" ===

Sandro: /* Development */

2025-11-08T04:38:27Z

Development

← Older revision		Revision as of 04:38, 8 November 2025
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	}		}
	</syntaxHighlight>		</syntaxHighlight>

	~~Tip: if you want use clang-format, add '''clang-format''' to '''buildinputs''' list.~~

	Also create '''.envrc''' file and paste: <code>use_nix</code> into it.		Also create '''.envrc''' file and paste: <code>use_nix</code> into it.

Sandro: /* Development */

2025-11-08T04:38:01Z

Development

← Older revision		Revision as of 04:38, 8 November 2025
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	pkgs.mkShell {		pkgs.mkShell {
	buildInputs = [		buildInputs = [
	pkgs.qt5.full		pkgs.qt5.full
	pkgs.qtcreator		pkgs.qtcreator
	];		];
	}		}
	</syntaxHighlight>		</syntaxHighlight>

Sandro: /* qt4 */

2025-11-08T04:37:38Z

qt4

← Older revision		Revision as of 04:37, 8 November 2025
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	=== This application failed to start because it could not find or load the Qt platform plugin ??? in "" ===		=== This application failed to start because it could not find or load the Qt platform plugin ??? in "" ===
	~~==== qt4 ====~~
	~~Qt4 depends on the environment variable <code>QT_PLUGIN_PATH</code> to find plugins. It is normally already~~
	present in the environment on NixOS at least, but for example systemd user units are launched in a pretty empty environment. A solution is to use the command {{Commands\|systemctl --user import-environment QT_PLUGIN_PATH}} from a sane environment. For example add it to the <code>services.xserver.displayManager.sessionCommands</code> option.

	==== qt5 ====		==== qt5 ====
	{{warning\|This recommendation is deprecated for 19.09 and up, see {{issue\|65399}}. Failing packages should be updated to use <code>wrapQtAppsHook</code>.}}		{{warning\|This recommendation is deprecated for 19.09 and up, see {{issue\|65399}}. Failing packages should be updated to use <code>wrapQtAppsHook</code>.}}

Tarix29: Fix syntax error in example code for specifying explitit Qt dependencies

2025-06-15T22:34:42Z

Fix syntax error in example code for specifying explitit Qt dependencies

← Older revision		Revision as of 22:34, 15 June 2025
Line 32:		Line 32:
	However if fetching the entirety of <code>pkgs.qt6.full</code> is not appealing and you know which parts of Qt you need, your first instinct might be adding something like <code>pkgs.qt6.qtdeclarative</code> for creating QML-based Qt programs to <code>buildInputs</code>, '''however''' that will not work and you will get compile errors for missing libraries. <code>pkgs.qt6.full</code> is actually [https://github.com/NixOS/nixpkgs/blob/nixos-24.11/pkgs/development/libraries/qt-6/default.nix#L94-L144 creating an environment that contains all Qt libraries] that allows <code>qmake</code> and tools to find those libraries, so you must do the same and <code>pkgs.qt6.env</code> will help make one. For example:		However if fetching the entirety of <code>pkgs.qt6.full</code> is not appealing and you know which parts of Qt you need, your first instinct might be adding something like <code>pkgs.qt6.qtdeclarative</code> for creating QML-based Qt programs to <code>buildInputs</code>, '''however''' that will not work and you will get compile errors for missing libraries. <code>pkgs.qt6.full</code> is actually [https://github.com/NixOS/nixpkgs/blob/nixos-24.11/pkgs/development/libraries/qt-6/default.nix#L94-L144 creating an environment that contains all Qt libraries] that allows <code>qmake</code> and tools to find those libraries, so you must do the same and <code>pkgs.qt6.env</code> will help make one. For example:

	<~~syntaxHighlight~~ lang=nix>		<syntaxhighlight lang="nix">
	# shell.nix		# shell.nix
	{ pkgs ? import <nixpkgs> {} }:		{ pkgs ? import <nixpkgs> {} }:
Line 38:		Line 38:
	# pkgs.qt6.env already includes pkgs.qt6.qtbase		# pkgs.qt6.env already includes pkgs.qt6.qtbase
	# And using `with` to prevent a lot of typing.		# And using `with` to prevent a lot of typing.
	qtEnv = with pkgs.qt6; env "qt-custom-${qtbase.version}" {		qtEnv = with pkgs.qt6; env "qt-custom-${qtbase.version}" [
	[		qtdeclarative
	qtdeclarative		];
	]
	};
	in		in
	pkgs.mkShell {		pkgs.mkShell {
Line 53:		Line 51:
	];		];
	}		}
	</~~syntaxHighlight~~>		</syntaxhighlight>

	== Packaging ==		== Packaging ==

Jarrodsfarrell: Added a section for explicitly specifying development dependencies

2024-12-28T14:07:34Z

Added a section for explicitly specifying development dependencies

@@ Line 10: / Line 10: @@
 For using direnv, create a '''shell.nix''' file in the root of your project and paste these lines into it:
 <syntaxHighlight lang=nix>
 # shell.nix
@@ Line 27: / Line 28: @@
 Happy qt coding :)
 == Packaging ==

Qt - Revision history

Aura: Added nix lang on some code hightlight

Phobos: Updated grammar

Smudgebun: Added a warning for the deprecated Qt section

Sandro: /* Troubleshooting */

Sandro: /* Cannot mix incompatible Qt library (version 0x_____) with this library (version 0x_____) */

Sandro: /* Development */

Sandro: /* Development */

Sandro: /* qt4 */

Tarix29: Fix syntax error in example code for specifying explitit Qt dependencies

Jarrodsfarrell: Added a section for explicitly specifying development dependencies

Sandro: /* Cannot mix incompatible Qt library (version 0x_) with this library (version 0x_) */