https://en.wikipedia.org/robots.txt currently contains the following lines:
# Don't allow the Wayback Machine to index user-pages #User-agent: ia_archiver #Disallow: /wiki/User #Disallow: /wiki/Benutzer
This does not work as intended, and probably never did, see e.g.
While it corresponds to the Internet Archive's own advice here, that page may be outdated (it appears to have been created in 2002 or earlier). It might be that the user agent "ia_archiver" needs to be changed to "archive.org_bot " (see this IA posting from 2009).
Even if this fixes it, a colon should be appended to the #Disallow patterns, or it would also affect mainspace pages like [[User space]].