Month: August 2007

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Git underwhelms

I work on source code from two separate SVN
repositories. One of them is geographically remote. Working with the remote server is slow for ‘log’, ‘diff -r’, ‘blame’, etc. Due to my interest in distributed version control, and my desire for faster repository access, I decided to try git and git-svn. Doing ‘log’, ‘diff’, etc. with a local git repo is much faster, but on the whole, working in a git repo created with git-svn has been difficult and unrewarding. Perhaps it would be easier if others at my company were using git-svn and we could share ideas. Working with git and git-svn requires learning a new workflow, and I haven’t yet reached enlightenment.

Challenges with Git:

  • The Git Wiki is often out-of-date and/or incomplete (submodule support, for example).
  • No Nautilus, Konquerer, or Windows Explorer integration.
  • No KDevelop itegration.
  • git-gui should:
  • let me double-click on files listed in either “Staged Changes” or “Unstaged Changes” to edit the file. Or let me right-click and choose an “edit” option.
  • Let me use an external diff program such as meld or kdiff3. git-gui should let me set this up and use it. qgit has an external diff option (defaults to kompare), but it doesn’t use the working copy on the right hand side, so it’s not possible to use the diff tool to change the working copy file.

Challenges with Git-SVN: (More complicated to use than Subversion)

  • Two stage commit instead of single stage. ‘git commit’, ‘git-svn dcommit’
  • Error messages are cryptic, so I don’t know how to resolve the errors.
  • git-svn rebase doesn’t merge changes from upstream Subversion server into my working copy, and git-svn doesn’t tell me what workflow I should be using. So I ran git-svn fetch to pull upstream Subversion changes. Then I ran git-gui and chose Merge->Local. It told me something helpful. “You are in the middle of a change. File X is modified. You should complete the current commit before starting the merge. Doing so will help you abort a failed merge, should the need arise.” “git-svn rebase” should have told me
    the same thing.

Reasons to continue with Subversion:

  • Workflow is easier, less complex — perhaps because I’m used to it.
  • Windows Explorer integration via TortiseSVN.
  • IDE integration. Nearly every IDE supports or has a pluging for Subversion.
  • svnmerge.py gives me cherry-picking support (between branches within the same repository)
  • svnmerge.py remembers merges, so I don’t have to resolve the same
    conflicts twice.
  • I don’t need disconnected operation in my workplace.

I hope that in a year, Git, git-svn and developer tool integration will be more mature and thus rewarding to use. With the rapid development I see happening, it wouldn’t be surprising.

I will continue to use git-svn. It gives me the speed I need for working with log history, annotate and diff.

Update: I’ve come across Git for Computer Scientists, and seeing the pretty graphs leads me to believe that working with git requires an understanding of how git works.

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Junk Science: New Science Challenges Climate Alarmists?

Fox News reports on [Junk Science: New Science Challenges Climate Alarmists?]( http://www.foxnews.com/story/0,2933,292810,00.html)
Thursday, August 09, 2007

> … The new model predicts that, during the coming decade, average global
temperature will be 0.3 degrees Centigrade (plus/minus 0.21 degrees
Centigrade) higher than the 2004 average temperature.

> But can mathematical models really estimate global temperature change
within 0.3 degrees Centigrade when we don’t even know what the average
global temperature is to within 0.7 degrees Centigrade?

> As NASA’s alarmist-in-chief James Hansen admits, we have no definition
of what we are trying to measure in the context of average global
temperature. “For the global mean, the most trusted models produce a
value of roughly 57.2 degrees Fahrenheit, but it may easily be anywhere
between 56 and 58 degrees Fahrenheit and regionally, let alone locally,
the situation is even worse,” says Hansen.

> For a dimmer view of the concept of average global temperature, consider
the thoughts of renowned theoretical physicist Freeman Dyson who says
that average land temperature is “impossible to measure… is a fiction…
nobody knows what it is… there’s no way you can measure it.”

> The UK researchers (and most other climate alarmists) are even wrong on
the matter of 1998 being the warmest year on record – at least for the
U.S. According to a new analysis which discovered an error in a NASA
dataset, 1934 is the new warmest year on record for the U.S. In fact,
four of the warmest 10 years in the U.S. date from the 1930s while only
three date from the last 10 years. This is an embarrassing setback for
alarmists, especially since about 80 percent of manmade carbon dioxide
(CO2) emissions occurred after 1940.

[Read more…](http://www.foxnews.com/story/0,2933,292810,00.html)

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Global warming? Look at the numbers

The Canada National Post reports [Global warming? Look at the numbers](http://www.canada.com/nationalpost/columnists/story.html?id=61b0590f-c5e6-4772-8cd1-2fefe0905363 )

>Last week, NASA’s Goddard Institute for Space Studies — whose temperature records are a key component of the global-warming claim (and whose director, James Hansen, is a sort of godfather of global-warming alarmism) — quietly corrected an error in its data set that had made recent temperatures seem warmer than they really were…. The hottest year since 1880 becomes 1934 instead of 1998, which is now just second; 1921 is third…. Perhaps we will have uncontrollable warming in the future, but it likely hasn’t started yet.