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Fedora provides leksah packages

Leksah is now in Fedora stable repositories. Available from Fedora 14 onwards.


New release 0.10.0 now available

Anyone using an earlier version should upgrade.

This release is mainly small improvements and bug fixes. Some of the improvements include:

  • Better messages for some common problems.
  • Improved grep (now searches all source directories in your workspace)
  • Updated build system for more reliable rebuilding of dependent packages in your workspace.

We have automated the building of the Leksah installers and this should allow us to do more frequent releases in the future.

There is a lot more to do and we would love to hear from anyone who has time to help out.

Worth mentioning because they can be hard to find:

  • <Ctrl> R adds missing imports
  • <Ctrl> <Enter> evaluates current line or selection in GHCi
  • Right click menu in the editor has other debug functions
  • Comment and uncomment are now <Ctrl> D and <Ctrl> <Shift> D

To build Leksah yourself:

  • Install Gtk and GtkSourceView2 (C libraries and headers)
  • Install The Haskell Platform (or GHC >= 6.12.3)
  • cabal update
  • cabal install gtk2hs-buildtools
  • cabal install leksah
  • leksah

Making a Gtk application look nice on Windows and OS X is not easy so we recommend using one of these prebuilt binaries:

Windows users using GHC 7.0.3 leksah-

Windows users using GHC 6.12.3 leksah-

OS X 10.6 users using GHC 7.0.3 Leksah-

(These installers do not install gtk2hs packages on your system)

Please consult for more details about installation! Background information can be found in the Leksah manual

Known bugs and problems:

Have Fun


Leksah repo moved to github

We had problems with, we had an inconsistency in the leksah repo, and I was missing GUI support for darcs. So we decided to use git.


Leksah packages now in Debian unstable. Please test.

Thanks to Joachim Breitner for packaging.


New #leksah IRC chat room on

Come and say hello. Thanks to dibblego for setting this up.


Leksah rpms for Fedora now available

Packages for Fedora 12 and Fedora13 for x86 and x86_64 platform are available now on the download page now!


Release 0.8 is out.

This is our official 0.8 release.  Anyone still using 0.6 should

Anyone using an earlier 0.8 release should upgrade too (and delete
~/.leksah-0.8/prefs.lkshp and ~/.leksah-0.8/prefscoll.lkshp).

There's lots of new stuff, so please have a look if you can. Let us know
which of the things that aren't there you think we should work on next.

Some changes in 0.8:

 * Workspaces (for working on projects with multiple packages)
 * Better metadata (includes nonexported definitions in workspace
 * Optional downloading of prebuilt metadata for packages
   (you can turn this off in the first start dialog)
 * Better completion (keywords, language extensions, module name,
   non exported definitions)
 * Split in a client and server part (Client part doesn't import
 * Compiles with GHC 6.12
 * Many bug fixes and little enhancements
 * Unstable and very limited Yi mode (vim bindings only for now)

Not new but worth mentioning:

 * <Ctrl> <Enter> evaluates current line or selection in GHCi
 * <Ctrl> R adds missing imports

To building Leksah yourself:

 * You need GHC 6.10 or 6.12 installed. The preferred way is current
   Haskell platform.    
 * You need Gtk2Hs including the GtkSourceView2 package.
   (Currently gtk2hs has no release for 6.12. On Linux we suggest you
   use the darcs version and install it via cabal install)
 * cabal install leksah  
 * leksah

Making a Gtk application look nice on Windows and OS X is not easy so
we recommend using one of these prebuilt binaries: (Windows) (OS X)

(Installation of gtk2hs for the development of gtk2hs apps is not done
by these installers. Please consult for
more details about installation! Background information can be found in
the Leksah manual:

Known bugs and problems:

 * If you have installed an earlier 0.8 version please delete your
   ~/.leksah-0.8/prefs.lkshp and ~/.leksah-0.8/prefscoll.lkshp

 * The server may occasionally allocate much memory, which has been
   observed on Windows. You can simply
   restart leksah (of leksah-server if you have started it separately)

 * leksah don't run with ghc-6.12.2


Updated manual for Leksah 0.8 now available.

Thanks to Andrew U. Frank and Christian Gruber. It still needs some corrections, but here it is:


Fedora packages for Leksah 0.8 prerelease available.

We have the rpms ready (for Fedora 12 i386 and x86_64). These packages are build with ghc-6.10.

Thanks to Lakshmi Narasimhan

Other needed rpms for 386 as tar.gz

Other needed rpms for x86_64 as tar.gz


Mac and Windows installers for Leksah 0.8 prerelease available

We have uploaded first pass at Windows and OSX binaries for 0.8. They are both built using GHC 6.12.1.

Installation: Make shure ghc 6.12.1 is installed.

Take care that wget and grep are on your path from a shell.

Please try them out if you can and let us know if you find any issues.



If the module browser has no modules in system, you need to do a ghc-pkg recache after installation.

Sorry, the user manual is not yet updated, but we are working on it.


Leksah 0.8 Prerelease

Please test our new prerelease, which we have published on Cabal.

We are in the process of preparing the next release of Leksah and are looking for people to test and report their experience. This prerelease may not be stable enough for productive work. If you like a minimum trouble upgrade you should wait till the release is officially announced.

Changes for 0.8 include:

  • Workspaces (for projects with multiple packages)
  • Better metadata with non exported definitions for workspace packages
  • Support for prebuild metadata packages
  • Better completion (keywords, language extensions, module name, non exported definitions)
  • Splitt in a client and server part (Client part doesn't import ghc-api)
  • Compiles with ghc 6.12 (Needs testing if it actually work)
  • Many bug fixes and little enhancements
  • Prepared for Yi (Abstract TextEditor interface, not ready for use)

We have published the first 0.8 packages to Hackage.


  • You need ghc 6.10.? or 6.12.? installed.
  • You need gtk2hs in a version compatible with ghc that includes the gtksourceview2 package.
  • cabal install leksah
  • start with: leksah

Known bugs and problems:

  • The release is still untested on ghc 6.12. It is currently not running in debugging mode under 6.12.
  • The server may occasionally allocate much memory. You can simply kill the process, and it will be restarted.
  • The automatic build may show some unexpected behaviour.
  • We are in the process of preparing the documentation but it is not updated yet.

Experimental 0.6 Fedora packages

We have new experimental rpms for Fedora 12 i686 platform, Currently the leksah rpm pulls in most of haskell platform dependencies. We are working on trimming some of the dependencies but the size of most of the libraries are not more than 40-50 KB.

use the following command, "yum --nogpgcheck install ghc-binary-devel-0.4.4-1.f12.i686.rpm leksah-0.6.10-1.f12.i686.rpm"

Kindly requesting you to try the installation on a Fedora 12 system and report back any failures found.

We are going to try the installation in Fedora 11 since it ships with ghc-6.10.1. Will update the results to the mailing list.


Experimental Mac and Windows installers

Please try out our new binary installers for Windows and Mac, which are available from the download page.


Release 0.6.0

Please try out our new binary installers for Windows and Mac, which are available from the download page.

The 0.6 version introduces a debugger mode. This mode can be switched on and off from the toolbar. In debugger mode expressions can be evaluated and the type of expressions can be shown. The GHCi debugger is integrated, so that breakpoints can be set, it is possible to step through the code and observe the values of variables. Other features of Leksah like building in the background and reporting errors on the fly work in debugger mode as in compiler mode.

Another new feature is integration of grep and text search with regular expression. This can be accessed from the findbar. The GUI framework has been enhanced, so that layouts can be nested in so called group panes. This feature is used for the debugger pane. Furthermore notebooks can be detached, so that Leksah can be used on multiple screens. A lot of little enhancements has been made and numerous bugs has been fixed.

Look in the manual for further information

GHC 6.10.2

Leksah does work with GHC version 6.10.2! But currently you have to get the repo version of gtk2hs and compile it (darcs get --partial In the gtk2hs repository the problems with changes on finalizers have been resolved.

Currently you have to change Cabal == to Cabal >= in the leksah.cabal file by hand. So you have to install leksah with runhaskell Setup configure (--user) ... We will fix this with the next release.



A minor fix for the recurring query to open a file:

  • Doesn't attempt a background build, when there is no open package.
  • Doesn't keep bugging the user if the session they select does not have a valid package
  • Improved title on package open dialog
  • Updated the manual for better Ubuntu installation description

Release 0.4.4

The changes from version 0.4.3 include:

  • Update of the manual with better installation description
  • Background build
  • Fix for MS Windows font issues
  • Bug fixes

Known bugs:

  • Background build not interruptible on Windows
  • Externally changed files not detected on Windows
  • Cabal files with configurations are not always rejected by the visual editor
  • Import helper sometimes don't integrate identifiers of the same module as expected
  • Main module not handled correctly in Metadata

User Manual Update

Uploaded a new version of the manual with some updated screenshots and a new explanation of metadata collection.


Release 0.4.3

  • Updated package/cabal editor
  • Move the top pane on a split
  • Added a welcome greeting (oh, so far with me)
  • Double click selects words with numbers

Release 0.4.2

This release needs a new session format. Throw away your old .session files.

  • Renamed usages pane to references (refs). Added scope to references
  • Command line option to extract cabal-install tars
  • fixed "first start" bug
  • import helper with ghc parser. Try this out!
  • fixed new module bug
  • Get rid of New. for gtk modelview
  • remember tree expansion in modules pane
  • text search takes current selection
  • changed "enter" key for text search to search forward.
  • recent files and packages added to menu

Release 0.4.1

  • File Save All: Default shortcut is Ctrl+Shift+S, New preference that allows you to specify if packageBuild should trigger fileSaveAll.
  • sharing in metadata serialization
  • Fix probably leak in the completion code.
  • passing language extensions to source collector parser.
  • new combo box now does something
  • first start bug.
  • reverted source collector to more primitive interface.
  • completion only on Ctrl-Space option
  • Fix: Issue 48 in leksah: Search-Replace with wrap-around crashes leksah
  • changed info and search panes to an easier and more convenient style
  • Better comment printing.
  • Add a note about the flipper to the manual
  • added completion!
  • simple docu search
  • Ctrl tab for notebook flipping
  • flipper with least recently used.

Prerelease 0.4

The 0.4 Release will become the first beta when it is stable enough. It is useable for practical work for the ones that wants to engage with it. I dropped backwards compatibility with ghc-6.8 and it will only work with ghc-6.10. It requires gtk2hs 0.10. A release is available from the gtk2hs webside.