In order to purge the temporary context files I did (throught an alias) texutil --purge
This worked fine.
Since the introduction of the ruby scripts this call now tells me:
remark: 'texutil' is now part of 'texexec'
warning: use 'texmfstart texutil' instead
So I obediently call:
texmfstart.rb texutil --purge
This silently does nothing.
Neither does work "texmfstart texexec --version" the same as did "texexec --version".
The former giving the TeXExec version, the latter gave the installed ConTeXt formats.
It is not "texmfstart texexec --purge" because I tried that too.
On the other hand, replacing "texexec --silent --pdf --autopdf file.tex"
by the same preceded with "texmfstart" does work as expected.