git-annex/doc/bugs/Android_chroot_stuck_in_Cabal_hell.mdwn

### Please describe the problem.
I'm trying to get an Android development environment set up, but I am running into conflicting library versions inside of the chroot. The package installation script now finishes, but I run into a link-time error during `cabal configure` because it is pulling in two different versions of the unix package for some reason. Please let me know if there is any information I can get from my build environment that would help diagnosing the issue.

### What steps will reproduce the problem?
Run `buildchroot`, `install-haskell-packages`, `make android`

### What version of git-annex are you using? On what operating system?
Attempting to build from source, cross-compiling for Android on Debian Jessie.

### Please provide any additional information below.

[[!format sh """
Linking ./dist/setup/setup ...
/usr/lib/ghc/unix-2.6.0.1/libHSunix-2.6.0.1.a(execvpe.o): In function `pPrPr_disableITimers':
(.text+0x300): multiple definition of `pPrPr_disableITimers'
/home/builder/.cabal/lib/i386-linux-ghc-7.6.3/unix-2.7.1.0/libHSunix-2.7.1.0.a(ghcrts.o):ghcrts.c:(.text+0x0): first defined here
collect2: error: ld returned 1 exit status
Makefile:225: recipe for target 'android' failed
make: *** [android] Error 1
"""]]

> [[fixed|done]] --[[Joey]]
2016-03-21 05:04:58 +00:00			`### Please describe the problem.`
			I'm trying to get an Android development environment set up, but I am running into conflicting library versions inside of the chroot. The package installation script now finishes, but I run into a link-time error during `cabal configure` because it is pulling in two different versions of the unix package for some reason. Please let me know if there is any information I can get from my build environment that would help diagnosing the issue.

			`### What steps will reproduce the problem?`
			Run `buildchroot`, `install-haskell-packages`, `make android`

			`### What version of git-annex are you using? On what operating system?`
			`Attempting to build from source, cross-compiling for Android on Debian Jessie.`

			`### Please provide any additional information below.`

			`[[!format sh """`
			`Linking ./dist/setup/setup ...`
			/usr/lib/ghc/unix-2.6.0.1/libHSunix-2.6.0.1.a(execvpe.o): In function `pPrPr_disableITimers':
			(.text+0x300): multiple definition of `pPrPr_disableITimers'
			`/home/builder/.cabal/lib/i386-linux-ghc-7.6.3/unix-2.7.1.0/libHSunix-2.7.1.0.a(ghcrts.o):ghcrts.c:(.text+0x0): first defined here`
			`collect2: error: ld returned 1 exit status`
			`Makefile:225: recipe for target 'android' failed`
			`make: *** [android] Error 1`
			`"""]]`
pin unix to already installed version This prevents multiple versions of unix, from ghc and needed by newer versions of some packages conflicting. Had to update the bytestring and blaze-builder pins follow-on from this change. 2016-04-28 18:21:57 +00:00
			`> [[fixed\|done]] --[[Joey]]`