[4/18/2010]

Version 0.6.2

A costly proposition

New features:
- [all] Resolver tiers are dead, long live resolver costs.
  
  The resolver now supports a flexible system of multi-leveled costs, in place of the fairly rigid tiers of previous releases. The default behavior emulates how tiers worked, but the resolver can also be configured with custom cost vectors by setting Aptitude::ProblemResolver::SolutionCost to something like this:
```
canceled-actions + 2*removals, ignored-recommends, installs
```
  That says to minimize the number of packages kept at their current version plus twice the number of removals (i.e., a removal counts for two keeps). Within that group, ties are broken by looking at the number of Recommends that were ignored, and within that group, ties are broken by looking at the number of new packages the resolver wants to install.
  
  In addition to custom cost vectors, resolver hints can be used to create completely custom costs.
  
  See the reference manual for full details.
  
  This is not optimized and I expect that pushing it to the limits will show off all sorts of exponential explosions. Have fun!
- [cmdline] Implemented an "aptitude versions" command that I've been kicking around for a while, to display and search for individual package versions. Documented in the manpage, but here are some highlights:
```
$ aptitude versions apt
i   0.7.25.3                         unstable     500
p   0.7.26~exp3                      experimental 1

$ aptitude versions '^apt$ ?installed'
Package apt
i   0.7.25.3                         unstable     500

$ aptitude versions xserver-xorg udev
Package udev:
i   151-2                                         100
p   151-3                            unstable     500

Package xserver-xorg:
i A 1:7.5+3                                       100
p A 1:7.5+5                          unstable     500

$ aptitude versions --group-by=source-package '?name(aptitude)'
Source package aptitude:
i   aptitude 0.6.1.5-2                            100
p   aptitude 0.6.1.5-3               unstable     500
i   aptitude-dbg 0.6.1.5-2                        100
p   aptitude-dbg 0.6.1.5-3           unstable     500
i   aptitude-doc-cs 0.6.1.5-2                     100
p   aptitude-doc-cs 0.6.1.5-3        unstable     500
```
(... many more lines of output snipped ...)
Crashes and serious errors:
- [cmdline] Don't crash if the user sets a rejection at the internal command-line via package name and version rather than using the new pick-by-numbers UI. (Closes: bug #567242)
- [cmdline] Don't crash if the user asks to see information about a removal.
- [cmdline] Don't crash in aptitude changelog when the package given on the command-line doesn't have a valid version (Closes: bug #576318). Thinks to Dmitry Semyonov for the patch.
Cosmetic and UI bugs:
- [curses] Don't leave a download progress bar hanging around after downloading a changelog. (Closes: bug #566205)
Internal changes:
- [all] Replaced mktemp() with a custom function doing a similar thing (albeit with slightly better randomness). This eliminates the spurious linker warning I've been ignoring for five years: the linker has no way to know that I only use mktemp() to create names in a mode 0700 directory, which is about the only way to use it safely.