After installing Postgres from official installer you’ll soon notice a new user on your Login screen, “Postgres”, to hide it perform the following:

sudo defaults write /Library/Preferences/com.apple.loginwindow HiddenUsersList -array-add postgres

After your log-out and login again you won’t be presented with that user, to reverse this change do:

sudo defaults delete /Library/Preferences/com.apple.loginwindow HiddenUsersList

More here

So when you install pow it also injects a rule in your firewall to route all traffic for port 80 to pow even if pow is shutdown, which kind of interfere’s with OSX Web Sharing MAMP, XAMP or whatever your using.

To get around this you could add:

export POW_DST_PORT=88

Then uninstall & re-install POW, it’ll see you want to use port 88 for POW, not install the firewall route and leave port 80 fine for web-sharing, you’ll have to add some extra rules in your apache vhosts to route traffic back to POW so it works again but then suddenly be restricted to needing Apache around which is just messy.

Alternatively you could forgo the .powconfig change, leave it on port 80 and the firewall rule intact and install a gem called POWDER to interfere with POW and something simple and easy for PHP serving like MAMP which will give you a full Apache/MySQL/PHP stack which you can start/stop as needed.

Now when you startup your machine POW will be running as normal, then when you need to play around with PHP you open the Terminal and type:

powder down

This will instruct POWDER to shutdown POW, remove the firewall fix and free up port 80 for MAMP. Now you can open up MAMP, tell it to use the default port 80 and work on your PHP sites

Once your finished open Terminal again and type:

powder up

This will instruct POWDER to resurrect POW, put back the firewall change and leave everything as normal so you can go ahead developing rails apps easily.

It’s a bit of a dirty hack but will keep you from pulling your hair out and burning time off that would be better spent on client work.

Thanks Rodreegez

Built right into OS X Lion, Lion Recovery lets you repair disks or reinstall OS X Lion without the need for a physical disc.

To do this all you’ll need is an external drive and the Recovery Tool available here http://support.apple.com/kb/dl1433.

To create an external Lion Recovery, download the Lion Recovery Disk Assistant application. Insert an external drive (no bigger than 1GB), launch the Lion Recovery Disk Assistant, select the drive or partition you would like it to install on, and follow the on screen instructions.

When the Lion Recovery Disk Assistant completes, the new partition will not be visible in the Finder or Disk Utility. To access Lion Recovery, reboot the computer while holding the Option key. Select Recovery HD from the Startup Manager.

F.Y.I. the Recovery Partition is usually 650mb in size.

If your getting something similar to this error:

-------------------------------------- Summary --------------------------------------
- 0 fatal error(s), 106 error(s), 0 warning(s)

ERROR: DW001: Set payload cancelled status

ERROR: DW049: Payload {007A2A28-D6A8-4D91-9A2B-568FF8052215} has an action "install" but no resultState
ERROR: DW049: Payload {0175676F-8C92-49F2-9131-D0D6AD654B41} has an action "install" but no resultState
ERROR: DW049: Payload {03FB981A-5170-11E0-A90E-3CEDE2AB3DC5} has an action "install" but no resultState
ERROR: DW049: Payload {08EF22BC-43B2-4B4E-BA12-52B18F418F38} has an action "install" but no resultState
ERROR: DW049: Payload {0A186736-9C62-48B2-B1DF-8A9C5CF7C997} has an action "install" but no resultState
ERROR: DW049: Payload {0CCF0458-5171-11E0-BC45-DC59E3AB3DC5} has an action "install" but no resultState
ERROR: DW049: Payload {0D96CFE6-376D-44B8-808A-16F3BEB73263} has an action "install" but no resultState
ERROR: DW049: Payload {0DFE8222-EDF8-4D17-8CCE-614D630A32F5} has an action "install" but no resultState
ERROR: DW049: Payload {11E1188F-E576-47BC-B215-600C02C7EABF} has an action "install" but no resultState
ERROR: DW049: Payload {128cd5a7-6018-4360-b4c0-b0258b1a5a34} has an action "install" but no resultState
ERROR: DW049: Payload {1A1E5FF9-D0FD-42A3-8E18-E5E7E95E1AB4} has an action "install" but no resultState
ERROR: DW049: Payload {22C26C10-5C22-4674-A52C-100112664305} has an action "install" but no resultState
ERROR: DW049: Payload {270C312D-7EC7-474C-BEB2-79CD398E02A3} has an action "install" but no resultState
ERROR: DW049: Payload {2EA9B52E-8613-41A0-9EEF-FF54AD4CC810} has an action "install" but no resultState
ERROR: DW049: Payload {3450d4c5-a82b-4428-a512-842ee1555a14} has an action "install" but no resultState
ERROR: DW049: Payload {37AB3C65-E02C-4DCF-B0E0-4C2E253D8FA3} has an action "install" but no resultState
ERROR: DW049: Payload {3D51982E-45C6-4B4B-9362-B356E1610821} has an action "install" but no resultState

This looks to be caused by not having the necessary JAVA libraries on your system (typically the case with fresh installs of OSX as they come without JAVA by default), to fix this install the JAVA Update for OSX Lion http://support.apple.com/kb/DL1421

Once installed reboot & try installing again, if this time the installer simply hangs or beach balls on “Calculating Size” then it could be down to your user not having full rights to install services as ROOT, even though it asks you for your administrator password.

A simple way to fix this is to add your user to the WHEEL group, which is linked to root and has full permissions.

To do this, open Terminal then type:

sudo dseditgroup -o edit -u yourusername -p -a yourusername -t user wheel

Replacing yourusername with your actual username, found by typing:

id

in terminal, you should see the first line similar to this,

uid=501(johnsmith)

in this case my username is johnsmith

once done you should now see you’ve been added to the group wheel

Restart your computer and re-run the installer, it should start to install now.

UPDATE: after still more problem we found that installing Adobe Flash Player manually allowed the installer to work and finally install.

…really wish Adobe would clean up their act with this, especially with what they’re charging us for.

OSX Lion is the latest incarnation of Apple’s flagship operating system and last week the official GM seed was sent to developers for testing. Yesterday I put it through it’s paces and have been happily surprised with the performance and improvements laid out in the latest release, attached is a quick video of Lion in action in all it’s one solid O/S.

To note,

• Launchpad for Apps (iOS)
• Mission Control
• FaceTime now integrated
• Address Book UI upgraded (more like iOS Books)
• Reset User Password via Apple ID
• Touchpad Gestures now a core part of the O/S
• Masses of UI improvements, gone and the rounded corners.
• Can set specific desktop background per Virtual Desktop / Space
• Fancy drag animation when moving files (gets out of the way of the cursor)
• Loads more…

On the App side everything still works pretty well, the following apps operate fine on Lion:

• Photoshop CS5
• Transmit
• Coda
• CornerStone SVN
• CSS Edit
• OmniGraffle
• VLC
• Tower
• TextMate
• MAMP & MAMP Pro

These Apps have visual problems that need fixing for Lion:

• Versions (opens main window & other regardless, sidebar cut-off)
• Espresso (desktop background seeps into interface)

Regarding official release date for OSX Lion my gut feeling says mid-July, in all the builds done and dusted just up to Apple to sign-off on things so you may be lucky and find it in the App Store this Tuesday.

Nice work Apple.