missing dependencies on debian stretch

[tbalbers]

So, this is a standard Debian Stretch, just updated.

Upgrading iridium-browser fails on a libfontconfig1 dependency. The dependency does not seem to be available in Stretch at all.
`
tba@pc588:~$ cat /etc/debian_version
9.4

tba@pc588:~$ sudo apt list --installed |grep iridium

WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

iridium-browser/now 2017.10-1iridium0 amd64 [installed,upgradable to: 2018.5.67-1iridium1]
tba@pc588:~$ sudo apt upgrade iridium-browser
Reading package lists... Done
Building dependency tree
Reading state information... Done
Calculating upgrade... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
iridium-browser : Depends: libfontconfig1 (>= 2.11.94) but 2.11.0-6.7+b1 is to be installed
E: Broken packages
tba@pc588:$
tba@pc588:$ sudo apt list --installed |grep libfontconfig1

WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

libfontconfig1/stable,now 2.11.0-6.7+b1 amd64 [installed,automatic]
libfontconfig1-dev/stable,now 2.11.0-6.7+b1 amd64 [installed,automatic]`

I have this issue on 5 machines now, running either Debian Stretch or SolydX.