Tips and Tricks for committers

This page provides some useful hints how to work with our infrastructure. And they can also make your work a lot easier.

Contents

1. Apply patches directly from Trac URL
2. Do Explorative Programming in tclsh with Readline Support
3. Debugging Tcl scripts
4. Portfile syntax highlighting
5. Checksum tips
6. Testing Port Phases
7. Searching for ports of a specific maintainer

Apply patches directly from Trac URL

Installation

Add the following functions to your .bashrc in order to apply patches directly from Trac.

function trac-get {
    local url=$1
    local dir=$2

    if [ -z $dir ]; then
        dir=.
    fi  

    curl "$url?format=raw" --create-dirs -o $dir/$(basename $1)
}

function trac-patch {
    local cmd=""

    while [[ $1 == -* ]]; do
        if [ "$1" == "--" ]; then
            break
        fi

        cmd="$cmd $1"
        shift
    done

    if [ -z $cmd ]; then
        cmd="--strip 0"
    fi

    trac-get $1

    patch $cmd < $(basename $1)
}

Usage

Use like this:

1. Copy the URL to the patch from the Trac ticket page
2. Switch to the ports directory

   $ cd $(port dir foo)
   

3. Apply the patch

   $ trac-patch https://trac.macports.org/attachment/ticket/.../Portfile.diff
   

You can also add options to trac-patch which will get passed through to the patch tool. This is especially useful when the patch needs another prefix level.

$ trac-patch -p1 https://trac.macports.org/attachment/ticket/.../Portfile.diff

If you don't add any option, -p0 is used as a default. This should be the most common case.

trac-get can also download to another directory. If the directory does not yet exist, it will be created. Just add a second parameter with the name of the directory. If you omit the second parameter, the current directory is used.

$ trac-get https://trac.macports.org/attachment/ticket/.../Portfile new-port

Do Explorative Programming in tclsh with Readline Support

tclsh does not offer readline support by itself, which is quite annoying. When writing portfiles or tinkering with changes to Macports base, I need to experiment in a Tcl shell all the time to tests small things. But for that, command history and Emacs-like navigation within the line are essential. Unfortunately tclsh does not offer this.

You can also use Emacs’ tcl-mode: from within a tcl buffer, the tcl shell is just a C-t away. More info in ​tcler’s wiki.

Solution: use port rlwrap together with tclsh. When you invoke tclsh via rlwrap you get all the convenience you know from bash.

rlwrap tclsh

Or, put even an alias into ~/.bashrc

alias tclsh='rlwrap tclsh'

and don't think about it ever again.

If you want to test MacPorts Tcl extensions, you need to require the appropriate packages. For access to the 'strsed', 'reinplace', and other macport commands, put the following into ~/bin/macports_testing.tcl:

package require macports
set portarchivemode no
mportinit
#package require port
package require Pextlib

[Note, Oct 2009] There may be a bug in the port 1.0 package, see ​http://lists.macosforge.org/pipermail/macports-dev/2009-September/010132.html

Then source the file in the Apple-supplied tclsh, i.e.:

$ rlwrap /usr/bin/tclsh
% source ~/bin/macports_testing.tcl
/opt/local
% strsed "foo" "s/f/m/"
moo
% 

Check self contained script too.

Debugging Tcl scripts

Tcl scripts can be debugged with the expect tool, which provides a debugging interface similar to gdb for those who are familiar with that. For a command overview, just type h at the prompt.

Run with:

$ expect -D1 <file> <args>

For example:

$ expect -D1 foo.tcl -bar
1: proc main {args} {
...
dbg1.0>

Portfile syntax highlighting

• BBEdit, TextWrangler
• ​TextMate
• ​vim

Checksum tips

Checksums for port updates

If you're updating a port's version and simply need the checksums for the new version, run the following while in the port's directory:

$ port -v checksum
...
The correct checksum line may be:
checksums           md5     1ca0cf40350913fa620f73cbd906378a \
                    sha1    2921531ece0eacb303b0c9a4978d0d050dcfd5d2 \
                    rmd160  6cacbcf37581b5e19fe9fe674dd7b0722f1a19de

You can then copy/paste the result into the Portfile. You should probably then manually tweak the whitespace of these lines to match the existing whitespace of the portfile to keep things consistent.

A bash script for checksums

#!/bin/bash
if [ -f "$1" ]; then
    basename $1 | sed -e "s/\(.*\)/\1 \\\/"
    md5 $1 | sed -e "s/^MD5.*=/md5/" | sed -e "s/\(.*\)/\1 \\\/"
    openssl sha1 $1 | sed -e "s/^SHA1.*=/sha1/" | sed -e "s/\(.*\)/\1 \\\/"
    openssl rmd160 $1 | sed -e "s/^R.*=/rmd160/"
fi

For example, assume this is in ~/bin/macports_checksum.bash, then we get:

$ macports_checksum.bash ~/Downloads/libpqxx-3.0.1.tar.gz 
libpqxx-3.0.1.tar.gz \
md5 23557f306821bf4cae39cca45acdf9e1 \
sha1 a37874511946ba340d5df2d92252177f9eb906f6 \
rmd160 1f842ea95ad6dd2cba2cdc2d2bd8e0be5063fb9b

Testing Port Phases

Individual port phases (fetch, checksum, extract, patch, configure, build, destroot, install and activate; see ​phases) can be run by using the appropriate keyword, e.g.:

port extract python26
port patch python26
port build python26

All phases that have not already been performed up to the designated phase will be run. If you want to rerun a port command that completed successfully, you can edit ./work/.macports.[port name].state and remove the lines up to the completed stage you want to keep.

By default, if the portfile is changed, you will get the message:

Portfile changed since last build; discarding previous state.

and the build directory will be removed (cleaned) before proceeding. When debugging a portfile, this can be avoided by using the '-o' flag (from the manpage):

-o       honor state files older than Portfile

Searching for ports of a specific maintainer

To find ports maintained by a particular maintainer, you can use the "maintainer:" pseudoport. Maintainers can list their email address in a port in ​several different ways, and you must search for all of them to be sure you find all relevant ports. For example, to print the name and maintainer(s) of all ports maintained by julesverne:

HANDLE=julesverne
port info --name --maintainer '(' \
"maintainer:(\s|^)$HANDLE(\s|$)" or \
"maintainer:(\s|^)$HANDLE@macports.org(\s|$)" or \
"maintainer:(\s|^)macports.org:$HANDLE(\s|$)" ')'

which will now find only those ports which HANDLE@macports.org maintains.