<html>
<head>
<meta http-equiv="Content-Type" content="text/html;
charset=windows-1252">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<p>Hi Simon,<br>
<br>
my first guess is that: when working on the unsaturated type
families paper, you did `cabal install --lib report`; or something
similar. `report` is probably some internal library to that paper
/ project.<br>
<br>
In that case, you are hitting the unfortunate cabal bug [1].<br>
<br>
To confirm, check what is in your
~/.ghc/x86_64-linux-8.6.5/environments/default (or similar), is
some `package-id report-0.1.0.0-hexhash` line there? If so, the
simplest fix is to remove that environment file.<br>
<br>
- [1] <a href="https://github.com/haskell/cabal/issues/5888">https://github.com/haskell/cabal/issues/5888
</a><a href="https://github.com/haskell/cabal/issues/5559">https://github.com/haskell/cabal/issues/5559<br>
</a></p>
<p>Cheers,<br>
Oleg</p>
<div class="moz-cite-prefix">On 30.5.2019 16.50, Simon Peyton Jones
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:DB7PR83MB0298E1AB4D66045B277382B0AD180@DB7PR83MB0298.EURPRD83.prod.outlook.com">
<meta http-equiv="Content-Type" content="text/html;
charset=windows-1252">
<meta name="Generator" content="Microsoft Word 15 (filtered
medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin-top:6.0pt;
margin-right:0cm;
margin-bottom:6.0pt;
margin-left:0cm;
font-size:11.0pt;
font-family:"Calibri",sans-serif;
mso-fareast-language:EN-US;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:#0563C1;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:#954F72;
text-decoration:underline;}
p.Code, li.Code, div.Code
{mso-style-name:Code;
margin-top:0cm;
margin-right:0cm;
margin-bottom:0cm;
margin-left:22.7pt;
margin-bottom:.0001pt;
font-size:10.0pt;
font-family:"Courier New";
mso-fareast-language:EN-US;
font-weight:bold;}
span.EmailStyle18
{mso-style-type:personal-compose;
font-family:"Calibri",sans-serif;
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri",sans-serif;
mso-fareast-language:EN-US;}
.MsoPapDefault
{mso-style-type:export-only;
margin-top:6.0pt;
margin-right:0cm;
margin-bottom:6.0pt;
margin-left:0cm;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 72.0pt 72.0pt 72.0pt;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
<div class="WordSection1">
<p class="MsoNormal">Dear friendly Cabal folk<o:p></o:p></p>
<p class="MsoNormal">Here’s what happened to me today<o:p></o:p></p>
<p class="Code">bash$ cabal install lhs2tex<o:p></o:p></p>
<p class="Code">cabal: Could not resolve dependencies:<o:p></o:p></p>
<p class="Code">[__0] next goal: report (user goal)<o:p></o:p></p>
<p class="Code">[__0] rejecting: report-0.1.0.0 (conflict:
requires UnsaturatedTypeFamilies)<o:p></o:p></p>
<p class="Code">[__0] fail (backjumping, conflict set: report)<o:p></o:p></p>
<p class="Code">After searching the rest of the dependency tree
exhaustively, these were the<o:p></o:p></p>
<p class="Code">goals I've had most trouble fulfilling: report<o:p></o:p></p>
<p class="MsoNormal">Crumbs. What is ‘report’? Why does it
need UnsaturatedTypeFamilies? I’m totally lost.<o:p></o:p></p>
<p class="MsoNormal">Then, in an inspired moment, I thought to
change to a different directory, ~/tmp.
<o:p></o:p></p>
<p class="MsoNormal">Then quite different things happened – it
downloaded and built relevant libraries.<o:p></o:p></p>
<p class="MsoNormal">I think that there just happened to be a
.cabal file in the original directory I was in at the time.
That appears to affect what ‘cabal install’ does in a truly
radical way.<o:p></o:p></p>
<p class="MsoNormal">My point is this: this is terribly
confusing for the user (at least for this on). I’d be
shocked if ‘apt install blah’ behaved utterly differently in
different directories. I’m going to make a little empty
directory somewhere, and cd to it before invoking cabal in
future. But that just feels like a workaround, not a
solution.<o:p></o:p></p>
<p class="MsoNormal">I’m not saying it’s wrong – just giving you
a data point that it had one user completely stumped<o:p></o:p></p>
<p class="MsoNormal">Simon<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="Code"><span
style="font-size:11.0pt;font-family:"Calibri",sans-serif"><o:p> </o:p></span></p>
</div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<pre class="moz-quote-pre" wrap="">_______________________________________________
cabal-devel mailing list
<a class="moz-txt-link-abbreviated" href="mailto:cabal-devel@haskell.org">cabal-devel@haskell.org</a>
<a class="moz-txt-link-freetext" href="http://mail.haskell.org/cgi-bin/mailman/listinfo/cabal-devel">http://mail.haskell.org/cgi-bin/mailman/listinfo/cabal-devel</a>
</pre>
</blockquote>
</body>
</html>