Question

Stack新手。我开始构建concurrent web scraper，然后运行stack new my-project simple。在my-project.cabal中，我必须为hxt，url，http和maybet插入依赖项。

executable my-project
  hs-source-dirs:      src
  main-is:             Main.hs
  default-language:    Haskell2010
  build-depends:       base >= 4.7 && < 5,
                       time,
                       hxt,
                       http,
                       maybet

当我运行stack build时，我明白了：

Error: While constructing the build plan, the following exceptions were encountered:

In the dependencies for my-project-0.1.0.0:
    http must match -any, but the stack configuration has no specified version
    maybet must match -any, but the stack configuration has no specified version
needed since my-project is a build target.

Some potential ways to resolve this:

  * Set 'allow-newer: true' to ignore all version constraints and build anyway.

  * You may also want to try using the 'stack solver' command.

在可执行指令下插入allow-newer: true似乎不起作用，添加http == *等版本后缀会出现解析错误，并根据hackage docs给出http == 4000.3.9,给了我http must match ==4000.3.9, but the stack configuration has no specified version

有没有一种简单的方法可以告诉cabal文件我想要最新版本？

Answer 1

Hackage中没有名为http的包。但是你有一个名为HTTP的包。

因此，修复软件包名称可以解决问题。

（此外博客文章似乎已经过时了，这些天通过conduit / wreq / req执行HTTP请求的标准方式）。

Haskell堆栈版本依赖项

1 个答案: