#562: cabal-install update fails going through a HTTP proxy

Valery V. Vorotyntsev valery.vv at gmail.com
Mon Nov 23 07:27:36 EST 2009

On Mon, Nov 16, 2009 at 11:15 PM, Valery V. Vorotyntsev
<valery.vv at gmail.com> wrote:

> Cabal client reinstalled with "patched" HTTP-4000.0.8 was still having
> occasional failures today. My proxy-POC.hs always succeeded, while
> cabal failed quite often with familiar
>    cabal: Codec.Compression.Zlib: premature end of compressed stream
> This means that proxy-POC.hs is not trustworthy: it doesn't expose the
> bug in 100% cases.
> I am going to roll back even further tomorrow: I'll patch [1]
> cabal-install to use strict ByteStrings and see if /that/ does the
> job.  (I'm not sure in anything any more.)
>  [1] http://hpaste.org/fastcgi/hpaste.fcgi/view?id=9447#a9504

Strict bytestrings in cabal-install do the job, yes.

> I've installed squid proxy server. Gotta make this bug exposable...

Downloading through local squid did not manifest the bug.

				* * *

Sigbjorn, I am stuck. If you have some idea on how to pursue this bug
(print debugging with Debug.Trace?), I'll be delighted to test it.

The bug is reproducible from within office LAN (read: ``business
hours, 8 am to 16 pm UTC''):

    $ cabal update -v3
    Downloading the latest package list from hackage.haskell.org
    GET http://hackage.haskell.org/packages/archive/00-index.tar.gz HTTP/1.1
    Proxy-Authorization: Basic SG93IGFyZSB5b3U/
    User-Agent: cabal-install/0.6.2
    Host: hackage.haskell.org
    proxy uri host: xproxy, port: :3128
    Creating new connection to xproxy:3128
    HTTP/1.0 200 OK
    Date: Mon, 23 Nov 2009 12:15:23 GMT
    Server: Apache/2.2.3 (Debian)
    Last-Modified: Mon, 23 Nov 2009 01:21:45 GMT
    ETag: "388dda-141754-a6117c40"
    Accept-Ranges: bytes
    Content-Length: 1316692
    Content-Type: application/x-tar
    Content-Encoding: x-gzip
    X-Cache: MISS from xproxy.foo.bar.ua
    X-Cache-Lookup: MISS from xproxy.foo.bar.ua:3128
    Via: 1.1 xproxy.foo.bar.ua:3128 (squid/2.7.STABLE6)
    Connection: close
    Downloaded to /home/vvv/.cabal/packages/hackage.haskell.org/00-index.tar.gz
    cabal: Codec.Compression.Zlib: premature end of compressed stream

Have fun!


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