On Thu, 2009-04-30 at 15:45 +0100, Alistair Bayley wrote:

On WinXP. I've uploaded Takusen-0.8.4 to hackage, and thought I'd see how well cabal-install downloads and installs it.

cabal install Takusen --flags="sqlite odbc oracle postgres" --reinstall -v3

results in (with some trimming):

... In order, the following would be installed: Takusen-0.8.4 (reinstall) Takusen-0.8.4 has already been downloaded. Extracting C:\Documents and Settings\bayleya\Application Data\cabal\packages\hackage.haskell.org\Takusen\0.8.4\Takusen-0.8.4.tar.gz to C:\DOCUME~1\bayleya\LOCALS~1\Temp\Takusen-0.8.411372... cabal: Error: some packages failed to install: Takusen-0.8.4 failed while unpacking the package. The exception was: user error (TAR checksum error)

The uploaded package was created with "darcs dist -d Takusen-0.8.4". Can I check before uploading that the tar file is valid?

Not easily at the moment I'm afraid. In future the server will use the same tar code and so will detect the non-portable tar archive format. There's no open ticket on this issue at the moment. Would you mind opening one? You can ensure that you are generating a portable tar archive by using cabal sdist rather than darcs dist. darcs calls gnu tar which can generate non-portable archives in some circumstances, eg when gnu tar is presented with long names etc. (In fact gnu tar by default generates non-standard archive formats, but a format that every recent archive program can understand, at least in its basic features). Or if you can get darcs dist to pass extra flags to gnu tar then you can pass --format=ustar or --format=posix. In the specific case of your Takusen-0.8.4.tar.gz, the latest version of cabal-install uses updated tar reading code that can grok some non-standard formats and so it doesn't actually complain about this example. Duncan