# What prevents elm-platform from using Haskell 8?

**URL:** <https://discourse.elm-lang.org/t/what-prevents-elm-platform-from-using-haskell-8/666>\
**Category:** Learn\
**Created:** [February 11, 2018, 5:36pm UTC](https://discourse.elm-lang.org/t/what-prevents-elm-platform-from-using-haskell-8/666 "2018-02-11T17:36:24Z")\
**Posts on this page:** 9\
**Page:** 1

<div class="post-metadata">

**Author:** ![bukzor](https://yyz1.discourse-cdn.com/flex035/user_avatar/discourse.elm-lang.org/bukzor/32/572_2.png) [@bukzor](https://discourse.elm-lang.org/u/bukzor)\
**Post date:** [February 11, 2018, 5:36pm UTC](https://discourse.elm-lang.org/t/what-prevents-elm-platform-from-using-haskell-8/666/1 "2018-02-11T17:36:24Z")

</div>

When I follow the[build from source](https://guide.elm-lang.org/install.html) installation directions, elm-platform rejects my ghc as being too new:

```auto
$ runhaskell installers/BuildFromSource.hs 0.17
You need GHC 7.10 to build this version of Elm.
You are using GHC 8.2 instead.

```

Out of curiosity, I hacked BuildFromSource.hs to allow my Haskell 8.2, and got the below errors, but I don’t know enough about the Haskell / Elm ecosystem to interpret them. Is this something that can be fixed by me?

```auto
$ runhaskell installers/BuildFromSource.hs master
Using GHC 8.2
Using Cabal 2.0.0.1

Cloning into 'elm-compiler'...
remote: Counting objects: 28784, done.
remote: Compressing objects: 100% (540/540), done.
remote: Total 28784 (delta 695), reused 778 (delta 476), pack-reused 27755
Receiving objects: 100% (28784/28784), 7.56 MiB | 2.06 MiB/s, done.
Resolving deltas: 100% (18141/18141), done.
Cloning into 'elm-package'...
remote: Counting objects: 3707, done.
remote: Total 3707 (delta 0), reused 0 (delta 0), pack-reused 3707
Receiving objects: 100% (3707/3707), 698.33 KiB | 99.00 KiB/s, done.
Resolving deltas: 100% (2204/2204), done.
Cloning into 'elm-make'...
remote: Counting objects: 1051, done.
remote: Total 1051 (delta 0), reused 0 (delta 0), pack-reused 1051
Receiving objects: 100% (1051/1051), 218.07 KiB | 155.00 KiB/s, done.
Resolving deltas: 100% (706/706), done.
Cloning into 'elm-reactor'...
remote: Counting objects: 3396, done.
remote: Total 3396 (delta 0), reused 0 (delta 0), pack-reused 3396
Receiving objects: 100% (3396/3396), 1.92 MiB | 105.00 KiB/s, done.
Resolving deltas: 100% (1948/1948), done.
Cloning into 'elm-repl'...
remote: Counting objects: 995, done.
remote: Total 995 (delta 0), reused 0 (delta 0), pack-reused 995
Receiving objects: 100% (995/995), 175.06 KiB | 762.00 KiB/s, done.
Resolving deltas: 100% (615/615), done.
Config file path source is default config file.
Config file /home/buck/.cabal/config not found.
Writing default configuration to /home/buck/.cabal/config
Downloading the latest package list from hackage.haskell.org
Writing a default package environment file to
/home/buck/repos/elm-platform/Elm-Platform/master/cabal.sandbox.config
Creating a new sandbox at
/home/buck/repos/elm-platform/Elm-Platform/master/.cabal-sandbox
Resolving dependencies...
cabal: Could not resolve dependencies:
trying: base-4.10.1.0/installed-4.1... (dependency of elm-compiler-0.19.0)
next goal: elm-make (user goal)
rejecting: elm-make-0.18 (conflict: elm-compiler==0.19.0, elm-make =>
elm-compiler==0.18)
rejecting: elm-make-0.1.2 (conflict: elm-compiler==0.19.0, elm-make =>
elm-compiler>=0.15 && <0.16)
rejecting: elm-make-0.1.1 (conflict: elm-compiler==0.19.0, elm-make =>
elm-compiler>=0.14.1 && <0.15)
trying: elm-make-0.1
next goal: optparse-applicative (dependency of elm-make-0.1)
rejecting: optparse-applicative-0.14.0.0, optparse-applicative-0.13.2.0,
optparse-applicative-0.13.1.0, optparse-applicative-0.13.0.0,
optparse-applicative-0.12.1.0, optparse-applicative-0.12.0.0,
optparse-applicative-0.11.0.2, optparse-applicative-0.11.0.1,
optparse-applicative-0.11.0 (conflict: elm-make => optparse-applicative>=0.10
&& <0.11)
rejecting: optparse-applicative-0.10.0 (conflict:
base==4.10.1.0/installed-4.1..., optparse-applicative => base>=4 && <4.8)
rejecting: optparse-applicative-0.9.1.1, optparse-applicative-0.9.1,
optparse-applicative-0.9.0, optparse-applicative-0.8.1,
optparse-applicative-0.8.0.1, optparse-applicative-0.8.0,
optparse-applicative-0.7.0.2, optparse-applicative-0.7.0.1,
optparse-applicative-0.7.0, optparse-applicative-0.6.0,
optparse-applicative-0.5.2.1, optparse-applicative-0.5.2,
optparse-applicative-0.5.1, optparse-applicative-0.5.0,
optparse-applicative-0.4.3, optparse-applicative-0.4.2,
optparse-applicative-0.4.1, optparse-applicative-0.4.0,
optparse-applicative-0.3.2, optparse-applicative-0.3.1,
optparse-applicative-0.3.0, optparse-applicative-0.2.0,
optparse-applicative-0.1.1, optparse-applicative-0.1.0,
optparse-applicative-0.0.1 (conflict: elm-make => optparse-applicative>=0.10
&& <0.11)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: elm-make, optparse-applicative, base,
elm-compiler
Note: when using a sandbox, all packages are required to have consistent
dependencies. Try reinstalling/unregistering the offending packages or
recreating the sandbox.
Resolving dependencies...
cabal: Could not resolve dependencies:
trying: base-4.10.1.0/installed-4.1... (dependency of elm-compiler-0.19.0)
next goal: elm-make (user goal)
rejecting: elm-make-0.18 (conflict: elm-compiler==0.19.0, elm-make =>
elm-compiler==0.18)
rejecting: elm-make-0.1.2 (conflict: elm-compiler==0.19.0, elm-make =>
elm-compiler>=0.15 && <0.16)
rejecting: elm-make-0.1.1 (conflict: elm-compiler==0.19.0, elm-make =>
elm-compiler>=0.14.1 && <0.15)
trying: elm-make-0.1
next goal: optparse-applicative (dependency of elm-make-0.1)
rejecting: optparse-applicative-0.14.0.0, optparse-applicative-0.13.2.0,
optparse-applicative-0.13.1.0, optparse-applicative-0.13.0.0,
optparse-applicative-0.12.1.0, optparse-applicative-0.12.0.0,
optparse-applicative-0.11.0.2, optparse-applicative-0.11.0.1,
optparse-applicative-0.11.0 (conflict: elm-make => optparse-applicative>=0.10
&& <0.11)
rejecting: optparse-applicative-0.10.0 (conflict:
base==4.10.1.0/installed-4.1..., optparse-applicative => base>=4 && <4.8)
rejecting: optparse-applicative-0.9.1.1, optparse-applicative-0.9.1,
optparse-applicative-0.9.0, optparse-applicative-0.8.1,
optparse-applicative-0.8.0.1, optparse-applicative-0.8.0,
optparse-applicative-0.7.0.2, optparse-applicative-0.7.0.1,
optparse-applicative-0.7.0, optparse-applicative-0.6.0,
optparse-applicative-0.5.2.1, optparse-applicative-0.5.2,
optparse-applicative-0.5.1, optparse-applicative-0.5.0,
optparse-applicative-0.4.3, optparse-applicative-0.4.2,
optparse-applicative-0.4.1, optparse-applicative-0.4.0,
optparse-applicative-0.3.2, optparse-applicative-0.3.1,
optparse-applicative-0.3.0, optparse-applicative-0.2.0,
optparse-applicative-0.1.1, optparse-applicative-0.1.0,
optparse-applicative-0.0.1 (conflict: elm-make => optparse-applicative>=0.10
&& <0.11)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: elm-make, optparse-applicative, base,
elm-compiler
Note: when using a sandbox, all packages are required to have consistent
dependencies. Try reinstalling/unregistering the offending packages or
recreating the sandbox.
Resolving dependencies...
cabal: Could not resolve dependencies:
trying: elm-reactor-0.18 (user goal)
trying: binary-0.8.5.1/installed-0.8... (dependency of scientific-0.3.5.2)
next goal: elm-package (dependency of elm-reactor-0.18)
rejecting: elm-package-0.18, elm-package-0.5, elm-package-0.4,
elm-package-0.2.2, elm-package-0.2.1, elm-package-0.2 (conflict:
binary==0.8.5.1/installed-0.8..., elm-package => binary>=0.7 && <0.8)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: primitive, vector, base, elm-reactor,
transformers, elm-compiler, Elm, elm-package
Note: when using a sandbox, all packages are required to have consistent
dependencies. Try reinstalling/unregistering the offending packages or
recreating the sandbox.

```

---

<div class="post-metadata">

**Author:** ![rob](https://yyz1.discourse-cdn.com/flex035/user_avatar/discourse.elm-lang.org/rob/32/589_2.png) [@rob](https://discourse.elm-lang.org/u/rob)\
**Post date:** [February 11, 2018, 5:49pm UTC](https://discourse.elm-lang.org/t/what-prevents-elm-platform-from-using-haskell-8/666/2 "2018-02-11T17:49:40Z")

</div>

If I read this correctly, you’re not just building with GHC 8.2, you’re also building the in-development elm version 0.19. And it’s not finding elm-make 0.19 to go with elm-compiler 0.19.

If you’re determined to keep going with this, how about trying to build 0.17 or 0.18 first (i.e., keep the `0.17` argument instead of `master`)?

---

<div class="post-metadata">

**Author:** ![bukzor](https://yyz1.discourse-cdn.com/flex035/user_avatar/discourse.elm-lang.org/bukzor/32/572_2.png) [@bukzor](https://discourse.elm-lang.org/u/bukzor)\
**Post date:** [February 11, 2018, 6:01pm UTC](https://discourse.elm-lang.org/t/what-prevents-elm-platform-from-using-haskell-8/666/3 "2018-02-11T18:01:24Z")

</div>

Thanks @rob. I’m trying that now. My reasoning was that, potentially, master branch has some new support for Haskell 8. I see that it cloned elm-make before it failed to find elm-make. Is that not the same one it’s supposed to find?

I got a very similar error when trying “0.18”:

```auto
Downloading the latest package list from hackage.haskell.org
Writing a default package environment file to
/home/buck/repos/elm-platform/Elm-Platform/0.18/cabal.sandbox.config
Creating a new sandbox at
/home/buck/repos/elm-platform/Elm-Platform/0.18/.cabal-sandbox
Resolving dependencies...
cabal: Could not resolve dependencies:
trying: transformers-0.5.2.0/installed-0.5... (dependency of union-find-0.2)
trying: elm-make-0.18 (user goal)
next goal: optparse-applicative (dependency of elm-make-0.18)
rejecting: optparse-applicative-0.14.0.0, optparse-applicative-0.13.2.0,
optparse-applicative-0.13.1.0, optparse-applicative-0.13.0.0,
optparse-applicative-0.12.1.0, optparse-applicative-0.12.0.0 (conflict:
elm-make => optparse-applicative>=0.11 && <0.12)
rejecting: optparse-applicative-0.11.0.2, optparse-applicative-0.11.0.1,
optparse-applicative-0.11.0 (conflict: transformers==0.5.2.0/installed-0.5...,
optparse-applicative => transformers>=0.2 && <0.5)
rejecting: optparse-applicative-0.10.0, optparse-applicative-0.9.1.1,

```

When trying “0.17.1”:

```auto
Downloading the latest package list from hackage.haskell.org
Writing a default package environment file to
/home/buck/repos/elm-platform/Elm-Platform/0.17.1/cabal.sandbox.config
Creating a new sandbox at
/home/buck/repos/elm-platform/Elm-Platform/0.17.1/.cabal-sandbox
Resolving dependencies...
cabal: Could not resolve dependencies:
trying: transformers-0.5.2.0/installed-0.5... (dependency of union-find-0.2)
trying: elm-make-0.17.1 (user goal)
next goal: optparse-applicative (dependency of elm-make-0.17.1)
rejecting: optparse-applicative-0.14.0.0, optparse-applicative-0.13.2.0,
optparse-applicative-0.13.1.0, optparse-applicative-0.13.0.0,
optparse-applicative-0.12.1.0, optparse-applicative-0.12.0.0 (conflict:
elm-make => optparse-applicative>=0.11 && <0.12)

```

When trying “0.17”:

```auto
Downloading the latest package list from hackage.haskell.org
Writing a default package environment file to
/home/buck/repos/elm-platform/Elm-Platform/0.17.1/cabal.sandbox.config
Creating a new sandbox at
/home/buck/repos/elm-platform/Elm-Platform/0.17.1/.cabal-sandbox
Resolving dependencies...
cabal: Could not resolve dependencies:
trying: transformers-0.5.2.0/installed-0.5... (dependency of union-find-0.2)
trying: elm-make-0.17.1 (user goal)
next goal: optparse-applicative (dependency of elm-make-0.17.1)
rejecting: optparse-applicative-0.14.0.0, optparse-applicative-0.13.2.0,
optparse-applicative-0.13.1.0, optparse-applicative-0.13.0.0,
optparse-applicative-0.12.1.0, optparse-applicative-0.12.0.0 (conflict:
elm-make => optparse-applicative>=0.11 && <0.12)

```

---

<div class="post-metadata">

**Author:** ![rob](https://yyz1.discourse-cdn.com/flex035/user_avatar/discourse.elm-lang.org/rob/32/589_2.png) [@rob](https://discourse.elm-lang.org/u/rob)\
**Post date:** [February 11, 2018, 6:23pm UTC](https://discourse.elm-lang.org/t/what-prevents-elm-platform-from-using-haskell-8/666/4 "2018-02-11T18:23:49Z")

</div>

But this is much better! Now you’re getting a proper version of elm-make (e.g., elm-make-0.18; before you had elm-make-0.1). I think the actual problem should be lower in your output. Chances are that some dependencies are rejected because GHC 8 comes with a new version of the `base` package. If that’s the case and you wanted to continue, the next step would be relaxing the version bounds in the cabal files.

By the way judging by the [travis config](https://github.com/elm-lang/elm-compiler/blob/master/.travis.yml) in `elm-lang/elm-compiler`, the development version is also being built with GHC 7.10, so it seems unlikely that master will be any easier here.

---

<div class="post-metadata">

**Author:** ![bukzor](https://yyz1.discourse-cdn.com/flex035/user_avatar/discourse.elm-lang.org/bukzor/32/572_2.png) [@bukzor](https://discourse.elm-lang.org/u/bukzor)\
**Post date:** [February 11, 2018, 6:42pm UTC](https://discourse.elm-lang.org/t/what-prevents-elm-platform-from-using-haskell-8/666/5 "2018-02-11T18:42:14Z")

</div>

Here’s the full message, below. It’s so long, I thought I’d try to shorten it to the most relevant bit, but it’s apparent I don’t know how 😃

```auto
$ runhaskell installers/BuildFromSource.hs 0.18
Using GHC 8.2
Using Cabal 2.0.0.1

fatal: destination path 'elm-compiler' already exists and is not an empty directory.
fatal: destination path 'elm-package' already exists and is not an empty directory.
fatal: destination path 'elm-make' already exists and is not an empty directory.
fatal: destination path 'elm-reactor' already exists and is not an empty directory.
fatal: destination path 'elm-repl' already exists and is not an empty directory.
Downloading the latest package list from hackage.haskell.org
Writing a default package environment file to
/home/buck/repos/elm-platform/Elm-Platform/0.18/cabal.sandbox.config
Using an existing sandbox located at
/home/buck/repos/elm-platform/Elm-Platform/0.18/.cabal-sandbox
Resolving dependencies...
cabal: Could not resolve dependencies:
trying: transformers-0.5.2.0/installed-0.5... (dependency of union-find-0.2)
trying: elm-make-0.18 (user goal)
next goal: optparse-applicative (dependency of elm-make-0.18)
rejecting: optparse-applicative-0.14.0.0, optparse-applicative-0.13.2.0,
optparse-applicative-0.13.1.0, optparse-applicative-0.13.0.0,
optparse-applicative-0.12.1.0, optparse-applicative-0.12.0.0 (conflict:
elm-make => optparse-applicative>=0.11 && <0.12)
rejecting: optparse-applicative-0.11.0.2, optparse-applicative-0.11.0.1,
optparse-applicative-0.11.0 (conflict: transformers==0.5.2.0/installed-0.5...,
optparse-applicative => transformers>=0.2 && <0.5)
rejecting: optparse-applicative-0.10.0, optparse-applicative-0.9.1.1,
optparse-applicative-0.9.1, optparse-applicative-0.9.0,
optparse-applicative-0.8.1, optparse-applicative-0.8.0.1,
optparse-applicative-0.8.0, optparse-applicative-0.7.0.2,
optparse-applicative-0.7.0.1, optparse-applicative-0.7.0,
optparse-applicative-0.6.0, optparse-applicative-0.5.2.1,
optparse-applicative-0.5.2, optparse-applicative-0.5.1,
optparse-applicative-0.5.0, optparse-applicative-0.4.3,
optparse-applicative-0.4.2, optparse-applicative-0.4.1,
optparse-applicative-0.4.0, optparse-applicative-0.3.2,
optparse-applicative-0.3.1, optparse-applicative-0.3.0,
optparse-applicative-0.2.0, optparse-applicative-0.1.1,
optparse-applicative-0.1.0, optparse-applicative-0.0.1 (conflict: elm-make =>
optparse-applicative>=0.11 && <0.12)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: optparse-applicative, elm-make, base,
elm-compiler, transformers, union-find
Note: when using a sandbox, all packages are required to have consistent
dependencies. Try reinstalling/unregistering the offending packages or
recreating the sandbox.
Resolving dependencies...
cabal: Could not resolve dependencies:
trying: transformers-0.5.2.0/installed-0.5... (dependency of union-find-0.2)
trying: elm-make-0.18 (user goal)
next goal: optparse-applicative (dependency of elm-make-0.18)
rejecting: optparse-applicative-0.14.0.0, optparse-applicative-0.13.2.0,
optparse-applicative-0.13.1.0, optparse-applicative-0.13.0.0,
optparse-applicative-0.12.1.0, optparse-applicative-0.12.0.0 (conflict:
elm-make => optparse-applicative>=0.11 && <0.12)
rejecting: optparse-applicative-0.11.0.2, optparse-applicative-0.11.0.1,
optparse-applicative-0.11.0 (conflict: transformers==0.5.2.0/installed-0.5...,
optparse-applicative => transformers>=0.2 && <0.5)
rejecting: optparse-applicative-0.10.0, optparse-applicative-0.9.1.1,
optparse-applicative-0.9.1, optparse-applicative-0.9.0,
optparse-applicative-0.8.1, optparse-applicative-0.8.0.1,
optparse-applicative-0.8.0, optparse-applicative-0.7.0.2,
optparse-applicative-0.7.0.1, optparse-applicative-0.7.0,
optparse-applicative-0.6.0, optparse-applicative-0.5.2.1,
optparse-applicative-0.5.2, optparse-applicative-0.5.1,
optparse-applicative-0.5.0, optparse-applicative-0.4.3,
optparse-applicative-0.4.2, optparse-applicative-0.4.1,
optparse-applicative-0.4.0, optparse-applicative-0.3.2,
optparse-applicative-0.3.1, optparse-applicative-0.3.0,
optparse-applicative-0.2.0, optparse-applicative-0.1.1,
optparse-applicative-0.1.0, optparse-applicative-0.0.1 (conflict: elm-make =>
optparse-applicative>=0.11 && <0.12)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: optparse-applicative, elm-make, base,
elm-compiler, transformers, union-find
Note: when using a sandbox, all packages are required to have consistent
dependencies. Try reinstalling/unregistering the offending packages or
recreating the sandbox.
Resolving dependencies...
cabal: Could not resolve dependencies:
trying: elm-reactor-0.18 (user goal)
trying: binary-0.8.5.1/installed-0.8... (dependency of scientific-0.3.5.2)
next goal: elm-package (dependency of elm-reactor-0.18)
rejecting: elm-package-0.18, elm-package-0.5, elm-package-0.4,
elm-package-0.2.2, elm-package-0.2.1, elm-package-0.2 (conflict:
binary==0.8.5.1/installed-0.8..., elm-package => binary>=0.7 && <0.8)
After searching the rest of the dependency tree exhaustively, these were the
goals I've had most trouble fulfilling: primitive, vector, base, elm-reactor,
transformers, elm-compiler, Elm, elm-package
Note: when using a sandbox, all packages are required to have consistent
dependencies. Try reinstalling/unregistering the offending packages or
recreating the sandbox.

```

---

<div class="post-metadata">

**Author:** ![bukzor](https://yyz1.discourse-cdn.com/flex035/user_avatar/discourse.elm-lang.org/bukzor/32/572_2.png) [@bukzor](https://discourse.elm-lang.org/u/bukzor)\
**Post date:** [February 11, 2018, 8:23pm UTC](https://discourse.elm-lang.org/t/what-prevents-elm-platform-from-using-haskell-8/666/6 "2018-02-11T20:23:00Z")

</div>

These were the changes that I had to make to the 0.18 cabal files to get things to install. I don’t know if this will break things (probably!). I plan to try it and see.

```auto
diff --git a/elm-make.cabal b/elm-make.cabal
index f49ba94..62bc4d8 100644
--- a/elm-make.cabal
+++ b/elm-make.cabal
@@ -67,7 +67,7 @@ Executable elm-make
         elm-package,
         filepath,
         mtl >= 2.2.1 && < 3,
- optparse-applicative >=0.11 && <0.12,
+ optparse-applicative >=0.11 && <0.14,
         raw-strings-qq,
         time,
         text
diff --git a/elm-package.cabal b/elm-package.cabal
index 4d64628..e91b906 100644
--- a/elm-package.cabal
+++ b/elm-package.cabal
@@ -67,7 +67,7 @@ Library
         edit-distance,
         elm-compiler == 0.18,
         filepath >= 1 && < 2.0,
- HTTP >= 4000.2.5 && < 4000.3,
+ HTTP >= 4000.2.5 && < 4000.4,
         http-client >= 0.4.15 && < 0.5,
         http-client-tls >= 0.2 && < 0.3,
         http-types >= 0.7 && < 0.9,
@@ -77,7 +77,7 @@ Library
         text,
         time,
         unordered-containers,
- vector >= 0.10 && < 0.12,
+ vector >= 0.10 && < 0.13,
         zip-archive
 
 
@@ -131,17 +131,17 @@ Executable elm-package
         edit-distance,
         elm-compiler == 0.18,
         filepath >= 1 && < 2.0,
- HTTP >= 4000.2.5 && < 4000.3,
+ HTTP >= 4000.2.5 && < 4000.4,
         http-client >= 0.3 && < 0.5,
         http-client-tls >= 0.2 && < 0.3,
         http-types >= 0.7 && < 0.9,
         mtl >= 2 && < 3,
         network >= 2.4 && < 2.7,
- optparse-applicative >= 0.11 && < 0.12,
+ optparse-applicative >= 0.11 && < 0.14,
         parallel-io,
         pretty,
         text,
         time,
         unordered-containers,
- vector >= 0.10 && < 0.12,
+ vector >= 0.10 && < 0.13,
         zip-archive

```

---

<div class="post-metadata">

**Author:** ![bukzor](https://yyz1.discourse-cdn.com/flex035/user_avatar/discourse.elm-lang.org/bukzor/32/572_2.png) [@bukzor](https://discourse.elm-lang.org/u/bukzor)\
**Post date:** [February 11, 2018, 10:52pm UTC](https://discourse.elm-lang.org/t/what-prevents-elm-platform-from-using-haskell-8/666/7 "2018-02-11T22:52:37Z")

</div>

Attempting to install Elm 0.18, using the above modifications, gives this result: [https://gist.github.com/bukzor/37dd35cb0a4e553e85e8f0a0f282432b](https://gist.github.com/bukzor/37dd35cb0a4e553e85e8f0a0f282432b). I’m going to give up now and install GHC 7. As a parting though, I see that the [Elm recipe in Homebrew](https://github.com/Homebrew/homebrew-core/blob/master/Formula/elm.rb#L48) uses GHC 8.0 to install Elm from source. Are all the problems I’m finding here specific to 8.2 but not 8.0?

```auto
Building executable 'elm-package' for elm-package-0.18..
[27 of 27] Compiling Utils.Paths ( src/Utils/Paths.hs, dist/dist-sandbox-ca0311fe/build/elm-package/elm-package-tmp/Utils/Paths.o )

src/Utils/Paths.hs:15:27: error:
    Not in scope: ‘N.toFilePath’
    No module named ‘N’ is imported.
   |
15 | library name = libDir </> N.toFilePath name
   | ^^^^^^^^^^^^

src/Utils/Paths.hs:19:26: error:
    Not in scope: ‘Package.versiontoString’
    Perhaps you meant one of these:
      ‘Package.versionToString’ (imported from Elm.Package),
      ‘Package.versionFromString’ (imported from Elm.Package)
    Module ‘Elm.Package’ does not export ‘versiontoString’.
   |
19 | library name </> Package.versiontoString version
| ^^^^^^^^^^^^^^^^^^^^^^^

```

---

<div class="post-metadata">

**Author:** ![rob](https://yyz1.discourse-cdn.com/flex035/user_avatar/discourse.elm-lang.org/rob/32/589_2.png) [@rob](https://discourse.elm-lang.org/u/rob)\
**Post date:** [February 12, 2018, 9:31am UTC](https://discourse.elm-lang.org/t/what-prevents-elm-platform-from-using-haskell-8/666/8 "2018-02-12T09:31:53Z")

</div>

Progress!

Those are some pretty straightforward errors, seems like that code was never compiled since 2015? Weird. Here’s an untested [patch](https://github.com/robx/elm-package/commit/54aa30d03eb28005dd478c82b4fab8bdc9e37ec7). Would you mind giving it a go?

---

<div class="post-metadata">

**Author:** ![jerith](https://yyz1.discourse-cdn.com/flex035/user_avatar/discourse.elm-lang.org/jerith/32/114_2.png) [@jerith](https://discourse.elm-lang.org/u/jerith)\
**Post date:** [February 19, 2018, 2:56am UTC](https://discourse.elm-lang.org/t/what-prevents-elm-platform-from-using-haskell-8/666/9 "2018-02-19T02:56:06Z")

</div>

The [nix expression for elm](https://github.com/NixOS/nixpkgs/tree/master/pkgs/development/compilers/elm) also uses something newer than upstream – in its case, 8.0.2. Maybe that’ll be of some help?

(Note, there was also some discussion of this at [https://github.com/elm-lang/elm-compiler/issues/1566](https://github.com/elm-lang/elm-compiler/issues/1566) – word there was that building with something newer than 7.10 is not a high priority right now.)