版本
%cabal --version
cabal-install version 3.6.2.0
compiled using version 3.6.2.0 of the Cabal library
%ghc --version
The Glorious Glasgow Haskell Compilation System, version 8.10.7
问题
我想安装weeder。如果当前目录中没有*.cabal文件，则运行cabal install weeder成功。但是，如果一个存在并且包含与weeder所需内容冲突的依赖项，则cabal install weeder将失败。
例如，如果.cabal文件包含text < 1.2.3.0作为build-depends，则cabal install weeder将失败，并显示以下消息：
%cabal install weeder
cabal: Could not resolve dependencies:
[__0] trying: foobarbaz-0.1.0.0 (user goal)
[__1] next goal: text (dependency of foobarbaz)
[__1] rejecting: text-1.2.4.1/installed-1.2.4.1 (conflict: foobarbaz =>
text<1.2.3.0)
[__1] skipping: text-1.2.5.0, text-1.2.4.1, text-1.2.4.0, text-1.2.3.2,
text-1.2.3.1, text-1.2.3.0 (has the same characteristics that caused the
previous version to fail: excluded by constraint '<1.2.3.0' from 'foobarbaz')
[__1] trying: text-1.2.2.2
[__2] next goal: deepseq (dependency of text)
[__2] rejecting: deepseq-1.4.4.0/installed-1.4.4.0 (conflict: text =>
base>=4.2 && <4.11, deepseq => base==4.14.3.0/installed-4.14.3.0)
[__2] trying: deepseq-1.4.5.0
[__3] next goal: array (dependency of text)
[__3] rejecting: array-0.5.4.0/installed-0.5.4.0 (conflict: text => base>=4.2
&& <4.11, array => base==4.14.3.0/installed-4.14.3.0)
[__3] trying: array-0.5.4.0
[__4] next goal: base (dependency of foobarbaz)
[__4] rejecting: base-4.14.3.0/installed-4.14.3.0 (conflict: text => base>=4.2
&& <4.11)
[__4] skipping: base-4.16.0.0, base-4.15.0.0, base-4.14.3.0, base-4.14.2.0,
base-4.14.1.0, base-4.14.0.0, base-4.13.0.0, base-4.12.0.0, base-4.11.1.0,
base-4.11.0.0 (has the same characteristics that caused the previous version
to fail: excluded by constraint '>=4.2 && <4.11' from 'text')
[__4] rejecting: base-4.10.1.0, base-4.10.0.0, base-4.9.1.0, base-4.9.0.0,
base-4.8.2.0, base-4.8.1.0, base-4.8.0.0, base-4.7.0.2, base-4.7.0.1,
base-4.7.0.0, base-4.6.0.1, base-4.6.0.0, base-4.5.1.0, base-4.5.0.0,
base-4.4.1.0, base-4.4.0.0, base-4.3.1.0, base-4.3.0.0, base-4.2.0.2,
base-4.2.0.1, base-4.2.0.0, base-4.1.0.0, base-4.0.0.0, base-3.0.3.2,
base-3.0.3.1 (constraint from non-upgradeable package requires installed
instance)
[__4] fail (backjumping, conflict set: base, foobarbaz, text)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: base, text, deepseq, array, foobarbaz
Try running with --minimize-conflict-set to improve the error message.
我可以通过在cabal install weeder之前的mv foobarbaz.cabal foobarbaz.cabal.bk和安装之后的mv foobarbaz.cabal.bk foobarbaz.cabal，或者在另一个目录中运行cabal install weeder来避免这种情况。但是是否有忽略本地.cabal文件的选项？
Cabal有一个--project-file选项。事实证明，当指定为空时，这会导致cabal安装不使用任何项目文件，即使在当前目录中也是如此。
cabal v2-install --project-file="" weeder
发布问题后，我发现-z和--ignore-project选项也是我想要的。
cabal install -z weeder