#780: Simpler support for isolated/sandboxed builds
---------------------------------+------------------------------------------
Reporter: duncan | Owner:
Type: enhancement | Status: new
Priority: normal | Milestone:
Component: cabal-install tool | Version:
Severity: normal | Keywords:
Difficulty: unknown | Ghcversion:
Platform: |
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Changes (by nathan.collins):
* cc: nathan.coll...@… (added)
Comment:
I just attempted my first "sandboxed" build with Cabal, and failed, and I
agree it could be much easier. After about 2 hours I was still failing,
and I came here to see if I had run into a bug. But, trying the Capri
package you mention above, I was able to figure out a sandboxed build in
about 5 minutes!
Here's where I gave up using `cabal` (some output elided here and in other
examples):
{{{
$ ghc-pkg init ./cabal/packages
$ prefix=`pwd`/cabal
$ cd lib/replib-read-only
$ cabal install --prefix $prefix --package-db=$prefix/packages
$ cd ../../src
$ cabal install --prefix $prefix --package-db=$prefix/packages
...
Loading package RepLib-0.3.1 ... linking ... done.
...
Registering trellys-core-0.0...
cabal: trellys-core-0.0: dependency
"RepLib-0.3.1-bd84a6d961076829097d3c4eb1eaee2c" doesn't exist (use --force
to
override)
cabal: Error: some packages failed to install:
trellys-core-0.0 failed during the building phase. The exception was:
ExitFailure 1
}}}
I wonder if this is a bug, because the failure was after building and
linking, and `ghc-pkg` knows about the package:
{{{
$ cd ..
$ ghc-pkg list --package-conf cabal/packages/ -v
using cache: cabal/packages/package.cache
using cache:
/home/collins/.ghc/i386-linux-6.12.1/package.conf.d/package.cache
using cache: /var/lib/ghc-6.12.1/package.conf.d/package.cache
cabal/packages/
RepLib-0.3.1 (RepLib-0.3.1-bd84a6d961076829097d3c4eb1eaee2c)
}}}
Now, here's the successful `capri` version, for comparison:
{{{
$ capri bootstrap
$ capri clone syb 'base-3*'
$ capri import lib/replib-read-only
$ capri import src
}}}
To be fair, the capri version had one hangup: in my first try I didn't
have the
{{{
$ capri clone syb 'base-*'
}}}
line, and I got
{{{
...
Linking dist/build/trellys/trellys ...
<command line>: unknown package: base-3.0.3.2
cabal: Error: some packages failed to install:
trellys-core-0.0 failed during the building phase. The exception was:
ExitFailure 1
}}}
in the `capri import src` step. But, a very similar error is covered in
the second example in the Capri documentation (which in total is 12 pages
in my browser, and onl y required skimming), so the solution was quickly
found.
Comparing the (failed) `cabal` version with the `capri` version, they're
both simple. The difference is that it took me 2 hours to come up with the
`cabal` version, versus 5 minutes to come up with the `capri` version.
The reason for the time difference is that `capri`'s (short) documentation
is all about doing what I wanted to do, whereas `cabal`'s (long)
documentation has no section devoted to sandboxed installs. So, assuming
there is an easy way to do this with `cabal`, it would probably be enough
to add a section to the documentation that explained the process for
people that want to move from a (working, but not sandboxed) install
process like
{{{
$ cd lib/replib-read-only
$ cabal install
$ cd ../../src
$ cabal install
}}}
to a sandboxed one.
P.S. the code I'm trying to build is a working copy of
https://code.google.com/p/trellys/, in case someone is dying to debug my
failed `cabal` sandboxed build :)
--
Ticket URL: <http://hackage.haskell.org/trac/hackage/ticket/780#comment:1>
Hackage <http://haskell.org/cabal/>
Hackage: Cabal and related projects
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