Skip to main content

Installing GHC 6.12.2 on Red Hat Entrprise Linux 5.4 (i386)

Haskell, a general-purpose, purely functional programming language, has become more and more interesting for me, it allows me to write maintainable code, with acceptable performance even for tasks like analyzing large log files. I recently discovered how easy it is to write programs interacting with a unix like environment. It also very easy to write networking code. Haskell offers great opportunities for TDD and SDD through HUnit and QuickCheck, which - together with the pure and strong static type system of the language itself - enable trust in program correctness, which is vital for many commercial applications, or applications exposed to increased security requirements.

In order to leverage the outstandingly great features of Haskell, one has to have that beast running on a stable, proven and hence archaic and outdated operating system. Even if one is not a firm believer in magical awesomeness of Enterprise labels on top of ridiculously obsolete tools(like gcc 4.1 and glibc 2.5), the server landscape might require to use a specific Linux distribution, because of proprietary drivers for specialized hardware components, in this post I will assume that this Linux distro is Red Hat Entrprise Linux 5.4 and explain the cumbersome installation of the latest and greatest Haskell compiler.

Step 0: Preparing the build environment


As a non-commercial 100% binary compatible replacement for RHEL with only the proprietary art work replaced Cent OS should be used. I installed Cent OS 5.4 i386 without any GNOME or KDE and with bridge networking in a Virtual Box with on an Arch Linux host.

Step 1: Installing GHC 6.8.3


Because the generic binary linux distribution of GHC 6.12.2 depends on at least the 2.7 version of glibc, and RHEL 5.4 only provides glibc 2.5, it is necessary to build it from the sources. Strangely the GHC source distribution needs an existing GHC to compile it: in order to compile GHC 6.12.2 from source we need to have a GHC already installed. The latest GHC version with a generic linux binray distribution compatible with glibc 2.5 is GHC 6.8.3.

These are the required commands(execute as root) to install GHC 6.8.3 into /usr/local:

[root@noname ~]# wget http://haskell.org/ghc/dist/6.8.3/ghc-6.8.3-i386-unknown-linux.tar.bz2
[root@noname ~]# tar xvfj ghc-6.8.3-i386-unknown-linux.tar.bz2
[root@noname ~]# cd ghc-6.8.3
[root@noname ghc-6.8.3]# ./configure
[root@noname ghc-6.8.3]# make install

Try running ghci, the interactive Haskell REPL, it should start and welcome its user with a warm...

[root@noname ~]# ghci
GHCi, version 6.8.3: http://www.haskell.org/ghc/ :? for help
Loading package base ... linking ... done.
Prelude>


Step 2: Building GHC-6.12.2


GHC 6.12.2 can now be built from source using the GHC 6.8.3 from the previous build...

wget http://haskell.org/ghc/dist/6.12.2/ghc-6.12.2-src.tar.bz2
tar xfvj ghc-6.12.2-src.tar.bz2
cd ghc-6.12.2
./configure
make

STOP do not make install just yet. Before, move your /usr/local/ to /usr/local.ghc683 in order to get a clean
install of GHC 6.12 in /usr/local with make install.

Harvest the result of your hard work


Now would be an excellent moment to save a snapshot of your /usr/local directory.
If I knew where I would even upload an archived version of mine.

Comments

Popular posts from this blog

Keys, Values and Rules: Three Important Shake Concepts

The title was a click-bait! This article will actually try to explain five instead of three important notions in Shake.

These are:
RulesKeysValuesThe Build DatabaseActions
This short blog post was inspired by the hurdles with my Shake based build, after the new Shake version was released, which had breaking API changes.

Jump to the next section if you are not interested in the why and how of this blog post.

Shake is rule based build system much like GNU make. Like make it is robust, unlike make, it is pretty fast and supports dynamic build dependencies.

But you knew all that already, if you are the target audience of this post, since this post is about me explaining to myself by explaining to you, how that build tool, I used for years, actually works.

Although I used it for years, I never read the paper or wrapped my head around it more than absolutely necessary to get the job done.

When Shake was updated to version 0.16.x, the internal API for custom rules was removed. Until then I w…

Lazy Evaluation(there be dragons and basement cats)

Lazy Evaluation and "undefined"
I am on the road to being a haskell programmer, and it still is a long way to go. Yesterday I had some nice guys from #haskell explain to me lazy evaluation.

Take a look at this code:

Prelude> let x = undefined in "hello world"
"hello world"
Prelude>

Because of Haskells lazyness, x will not be evaluated because it is not used, hence undefined will not be evaluated and no exception will occur.

The evaluation of "undefined" will result in a runtime exception:

Prelude> undefined
*** Exception: Prelude.undefined
Prelude>


Strictness
Strictness means that the result of a function is undefined, if one of the arguments, the function is applied to, is undefined.
Classical programming languages are strict. The following example in Java will demonstrate this. When the programm is run, it will throw a RuntimeException, although the variable "evilX" is never actually used, strictness requires that all
arguments of a fu…

Erlang mock - erlymock

NOTE THIS POST IS OUTDATED!
The project has evolved and can be found here: ErlyMock


Some features

Easy to use
Design based on easymock
Works together with otp: can be used even if the clut is called from another process, by invoking mock:verify_after_last_call(Mock,optional: timeout)
custom return functions
predefined return functions for returning values, receiving message, throwing exceptions, etc..
erlymock automatically purges all modules that were mocked, after verify()
Custom argument matchers:

%% Orderchecking types: in_order, out_of_order, stub;
%% Answering: {return, ...}|{error, ...}|{throw, ...}|{exit, ...}|{rec_msg, Pid}|{function, Fun(Args) -> RetVal}
expect(Mock, Type, Module, Function, Arguments, Answer = {AT, _}) when AT==return;AT==error;AT==throw;AT==exit;AT==rec_msg;AT==function ->
call(Mock, {expect, Type, Module, Function, length(Arguments), {Arguments, Answer}}).

%% this version of expect is suited for useing custom argument matchers
expect(Mock, Type, Module, Fun, …