Tcl/Tk 8.4 has reached it's end of life, so we should make packages stop using it. This includes porting packages to be compatible with Tcl/Tk 8.5 (which is currently the default version) and 8.6 (which will be the next default). Packages which don't require specific Tcl/Tk version should not explicitly depend or build-depend on specific versions (tcl8.x/tcl8.x-dev packages). tcltk-depends helper should be used.
When all packages have migrated to newer Tcl versions, Tcl/Tk 8.4 may be deprecated (possibly removed?). Similarly, when packages surely work with Tcl/Tk 8.6, it can be probably made a default version.
There are some packages which explicitly depend on tcl8.4 and tcl8.4-dev/tcl8.5-dev needlessly (which?).
There are few packages which fail to run when Tcl 8.6 is set as the default (which?).
How to help
- Update packages to build against newer Tcl/Tk versions (by providing patches and NMUing where necessary).
- Send patches for packages failing to run on Tcl/Tk 8.5 or 8.6.
- Report bugs on packages