On 3/16/12 6:00 AM, Erik de Castro Lopo wrote:
Hi all,
With a base system with just ghc and cabal-install, if I try to install bytestring-lexing I get:
$ cabal install bytestring-lexing Resolving dependencies... Configuring bytestring-lexing-0.4.0... cabal: The program alex version>=2.3 is required but it could not be found. cabal: Error: some packages failed to install: bytestring-lexing-0.4.0 failed during the configure step. The exception was: ExitFailure 1
The cabal file for bytestring-lexing contains
Build-Tools: alex>= 2.3
Is there any way to make the cabal install of bytestring-lexing force the install of alex first?
FWIW, the Alex dependency is part of the code I inherited when taking over bytestring-lexing. Apparently older versions of the library included pre-generated versions of the files that Alex builds, prior to when Cabal understood about build tools at all. I'm willing to go back that direction if that's what folks want--- especially if there's a way to tell Cabal to switch between the pregenerated files vs using Alex. I've noticed that the code generated by Alex causes a lot of warnings, some of them are of the "it will break in the future" variety. I've considered rewriting the parsers for Double manually, but I'm not sure exactly what the performance bottlenecks are in that context nor whether anyone is actually using the current functions in performance-critical regions. To Erik specifically: my emails to you off-list have been bouncing/timing out. Is there a chance I've ended up on a blacklist or there's some configuration issue at mega-nerd.com? -- Live well, ~wren