I am a beginner and I am trying to use OSCOLA Style with biblatex.
It's 2 days I am bashing my head on these errors:
Please help!
I am a beginner and I am trying to use OSCOLA Style with biblatex.
It's 2 days I am bashing my head on these errors:
Please help!
The issue is resolved in oscola v1.7 (2020/03/15) (see https://github.com/PaulStanley/oscola-biblatex/pull/8).
If possibly update your TeX system to obtain a current version of oscola.
The rest of the answer below is kept for historical interest.
This error occurs, because someone extended the scope of some of biblatex's standard.bbx options from global to per-type and per-entry, see https://github.com/plk/biblatex/pull/877 and https://github.com/plk/biblatex/issues/875 for background (https://github.com/plk/biblatex/pull/866 for even more background). Amongst the options whose scope was extended are url, doi and eprint.
biblatex will not accept attempts to define an option if it has been defined before and will throw an error. oscola already defines the options url, doi and eprint at per-type and per-entry scopes.
Unfortunately, someone forgot to check oscola for compatibility with the change, so the biblatex update went out before the oscola author could be made aware of this change and adapt his style.
The issue was only discovered a while later by Ulrike Fischer (https://chat.stackexchange.com/transcript/41?m=52383705#52383705) and for now documents using style=oscola, will complain
! Package biblatex Error: Option 'url' already defined.
See the biblatex package documentation for explanation.
Type H <return> for immediate help.
...
l.135 \settoggle{bbx:url}{#1}}
?
! Package biblatex Error: Option 'doi' already defined.
See the biblatex package documentation for explanation.
Type H <return> for immediate help.
...
l.137 \settoggle{bbx:doi}{#1}}
?
! Package biblatex Error: Option 'eprint' already defined.
See the biblatex package documentation for explanation.
Type H <return> for immediate help.
...
l.139 \settoggle{bbx:eprint}{#1}}
?
because biblatex's standard.bbx defines these options and then oscola.bbx tries to define them again.
A fix has been submitted to the oscola-biblatex GitHub repository: https://github.com/PaulStanley/oscola-biblatex/pull/8.
If you need to use oscola now, download oscola.bbx from the pull request (https://github.com/PaulStanley/oscola-biblatex/blob/28e6a54ef5c6d4b02e06cedee0123d7b92ec5857/oscola.bbx), put it into the same folder as your main .tex document, rename it to oscola-fixed.bbx and load biblatex as
\usepackage[bibstyle=oscola-fixed, citestyle=oscola, backend=biber]{biblatex}
instead of \usepackage[style=oscola, backend=biber]{biblatex}.