[Pkg-fonts-devel] Bug#808109: fonts-droid-fallback and fonts-droid: error when trying to install together

[Simon McVittie]

On Thu, 24 Dec 2015 at 16:55:47 +0530, Vasudev Kamath wrote:
> Ralf Treinen <treinen at free.fr> writes:
> > The version constraints on your Breaks and Replaces do not match the
> > current version of fonts-droid, which is 1:4.4.4r2-7 :
> >
> > Replaces: fonts-droid (<< 1:4.4.4r2-7~)
> > Breaks: fonts-droid (<< 1:4.4.4r2-7~)
> >
> > You should use something like "<= 1:4.4.4r2-7".
> 
> Ah okay. I'm just wondering what ~ actually means, IIRC its meant to be
> saying just before the version right?. 

1:4.4.4r2-7~ is a version slightly less than 1:4.4.4r2-7, and in particular
less than 1:4.4.4r2-7~deb8u1, but greater than (for example) a hypothetical
NMU 1:4.4.4r2-6.1. It's conventionally used in Breaks/Replaces
to allow a backporter to append "~deb8u1" or similar while staying on the
"newer version" side of the versioned Breaks.

>From the changelog:

> fonts-android (1:6.0.0r26-1) unstable; urgency=medium
...
>  * Use Breaks and Replaces on fonts-droid << 1.4.4.4r2-7.

This is incorrect. I think what you meant to do is "Breaks, Replaces:
fonts-droid versions that contained DroidSansFallback.ttf",
which you would spell as

    Breaks: fonts-droid (<< 1:6.0.0r26-1~)
    Replaces: fonts-droid (<< 1:6.0.0r26-1~)

It sounds as though Ralf is advising you to use "Breaks, Replaces:
fonts-droid versions less than or equal to the previous one", which
you would spell as

    Breaks: fonts-droid (<= 1:4.4.4r2-7)
    Replaces: fonts-droid (<= 1:4.4.4r2-7)

but that seems non-ideal to me: if there was an NMU 1:4.4.4r2-7.1
based on 1:4.4.4r2-7, then it would presumably still have shipped
DroidSansFallback.ttf and so on, so it cannot be co-installed
with 1:6.0.0r26-1.

    S