.nuget/packages/fable.elmish.browser/0.9.0/fable/prelude.fs" is not in the SourceMap

[aolney]

Oddly this template was working ~2 weeks ago, but now fails with this error. I've tried blowing away the .nuget directory, node_modules, npm cache, and downgrading node.

aolney@monkmonk:/z/aolney/repos/awesome/src$ dotnet fable yarn-run start
Fable (1.2.4) daemon started on port 61225
CWD: /z/aolney/repos/awesome
yarn run start
yarn run v1.2.1
$ webpack-dev-server
Bundling for development...
Project is running at http://localhost:8080/
webpack output is served from /
Content not from webpack is served from /z/aolney/repos/awesome/public
Parsing ./awesome.fsproj...
fable: Compiled src/awesome.fsproj
fable: Compiled src/App.fs
fable: Compiled ../../../../home/aolney/.nuget/packages/fable.elmish/0.9.2/fable/program.fs
fable: Compiled ../../../../home/aolney/.nuget/packages/fable.elmish.browser/0.9.0/fable/navigation.fs
fable: Compiled ../../../../home/aolney/.nuget/packages/fable.elmish.debugger/0.9.0/fable/debugger.fs
fable: Compiled src/Types.fs
fable: Compiled ../../../../home/aolney/.nuget/packages/fable.elmish.hmr/1.0.0/fable/hmr.fs
fable: Compiled ../../../../home/aolney/.nuget/packages/fable.elmish/0.9.2/fable/cmd.fs
fable: Compiled ../../../../home/aolney/.nuget/packages/fable.elmish.react/0.9.0/fable/react.fs
fable: Compiled src/CounterList/View.fs
fable: Compiled src/Navbar/View.fs
fable: Compiled src/State.fs
fable: Compiled src/Home/View.fs
fable: Compiled src/Counter/View.fs
fable: Compiled src/Info/View.fs
fable: Compiled ../../../../home/aolney/.nuget/packages/fable.react/1.2.1/fable/Fable.Helpers.React.fs
fable: Compiled ../../../../home/aolney/.nuget/packages/fable.elmish.browser/0.9.0/fable/parser.fs
fable: Compiled src/Counter/State.fs
fable: Compiled src/Home/State.fs
fable: Compiled ../../../../home/aolney/.nuget/packages/fable.elmish.react/0.9.0/fable/common.fs
fable: Compiled ../../../../home/aolney/.nuget/packages/fable.elmish.debugger/0.9.0/fable/Fable.Import.RemoteDev.fs
fable: Compiled src/CounterList/State.fs
fable: Compiled src/CounterList/Types.fs
fable: Compiled src/Home/Types.fs
fable: Compiled src/Counter/Types.fs
fable: Compiled ../../../../home/aolney/.nuget/packages/fable.elmish.browser/0.9.0/fable/prelude.fs
/z/aolney/repos/awesome/node_modules/source-map/lib/source-map-consumer.js:704
      throw new Error('"' + aSource + '" is not in the SourceMap.');
      ^

Error: "/home/aolney/.nuget/packages/fable.elmish.browser/0.9.0/fable/prelude.fs" is not in the SourceMap.
    at SourceMapConsumer_sourceContentFor [as sourceContentFor] (/z/aolney/repos/awesome/node_modules/source-map/lib/source-map-consumer.js:704:13)
    at /z/aolney/repos/awesome/node_modules/source-map/lib/source-node.js:139:40
    at Array.forEach (native)
    at Function.SourceNode_fromStringWithSourceMap [as fromStringWithSourceMap] (/z/aolney/repos/awesome/node_modules/source-map/lib/source-node.js:138:32)
    at SourceMapSource.node (/z/aolney/repos/awesome/node_modules/webpack-sources/lib/SourceMapSource.js:39:21)
    at ReplaceSource.node (/z/aolney/repos/awesome/node_modules/webpack-sources/lib/ReplaceSource.js:70:30)
    at CachedSource.node (/z/aolney/repos/awesome/node_modules/webpack-sources/lib/CachedSource.js:18:24)
    at /z/aolney/repos/awesome/node_modules/webpack-sources/lib/ConcatSource.js:37:50
    at Array.map (native)
    at ConcatSource.node (/z/aolney/repos/awesome/node_modules/webpack-sources/lib/ConcatSource.js:36:63)
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
Closing Fable daemon...
aolney@monkmonk:/z/aolney/repos/awesome/src$

[MangelMaxime]

I can't reproduce it.

Do you still have this error ?

[aolney]

It works now. I just upgraded Debian though, so that might have done something. Thanks!

[MangelMaxime]

I also updated the templates today so perhaps this helps too. Don't know

Happy to it solve 😊

[aolney]

I believe I figured out the problem. In my original post, you'll see the repo was located on my local drive at /z/aolney/repos/awesome. That folder is on a different filesystem than /home/aolney/.nuget. In other words, I have my root filesystem / on a partition, z on another partition, and then in my fstab I mount z onto / to get /z.

When I follow the install/build instructions for yarn AND I'm in my /home directory, it works as expected.

However, when I'm in /z/aolney/repos, then I receive the original reported error. It appears that somewhere in the build process the absolute filepath /home/aolney gets prepended with ../../../.. which is actually one level off.

So there are two apparent ways to solve this:

1. Force compilation to use the absolute path, e.g. fable: Compiled ../../../../home/aolney/... becomes fable: Compiled /home/aolney/...

2. Correct the relative path used in compilation (in my case adding an extra parent), e.g. fable: Compiled ../../../../home/aolney/... becomes fable: Compiled ../../../../../home/aolney/...

I'm happy to submit a PR for this, but I don't know where to start. A quick search around the repo doesn't clear this up, and I've used base fable templates in /z and not had this problem, so I don't think it is an issue with fable.

[MangelMaxime]

Are the others fable templates you used using storage: none setting for paket ?
https://github.com/fable-elmish/templates/blob/master/src/react/Content/paket.dependencies#L3

[alfonsogarciacaro]

Just to let you know, today I was actually thinking about a similar issue and for Fable 2 I'm planning to copy the sources of referenced Fable libraries (as well as fable-core JS files) to a .fable folder within the project directory to prevent this and other related problems.

[aolney]

@alfonsogarciacaro Thanks that sounds like it would help 👍

@MangelMaxime Yes other templates I'm using successfully have storage:none. I tried commenting out storage:none in the elmish project, rerunning mono .paket/paket.exe install, and then building, but I get the same error with relative paths like this:

fable: Compiled ../../../../home/aolney/.nuget/packages/fable.elmish.browser/1.0.0/fable/parser.fs

It doesn't seem like storage: none is affecting this behavior. Is there another setting that would?

[MangelMaxime]

I really don't know...

@alfonsogarciacaro Is it Fable or webpack who resolves the path of the files to parse ?

[alfonsogarciacaro]

The issue with the new fsproj format is it doesn't matter whether you let Paket download packages locally, MSBuild is going to always reference the assemblies in the .nuget global cache. Fable uses Dotnet.ProjInfo which calls MSBuild and gets the paths for the packages in the .nuget cache. These are the paths that are passed to Webpack.

Hopefully copying the content of the fable folder of Fable packages to a local folder will fix these issues, as Webpack and other tools usually expect paths within the project directory.

[MangelMaxime]

Thanks @alfonsogarciacaro for the explanations, so we will probably wait for Fable 2 and see if this solved the problems.

[aolney]

@alfonsogarciacaro Thanks for those insights. What's weird here is that the simple template works but the fable-elmish template does not. This makes me think there is some kind of configuration change that could be made to fable-elmish to get it to work. Unless perhaps you think that a change in dotnet-fable or related projects changed the behavior from 1.2.4 (what simple uses) to 1.3.3 (what fable-elmish uses)?

[alfonsogarciacaro]

@aolney TBH, I don't know 😕 Can you use the workaround for now until Fable 2 is ready? (hopefully in a few weeks)

[aolney]

No problem, thanks to you and @MangelMaxime for everything you do

[dustinlacewell-wk]

I just ran into this issue trying to build SAFE-Chat project inside of a Docker Image https://hub.docker.com/r/dcurylo/paket/ with the following Dockerfile:

from dcurylo/paket

run curl -sL https://deb.nodesource.com/setup_6.x | bash -

run apt-get update && apt-get -y install build-essential libssl-dev nodejs

run npm i yarn npm5 -g

copy . /app

workdir /app

run yarn install

workdir /app/src/Client

run dotnet restore
run dotnet fable webpack -p

With the resulting error:

docker run -it --rm safe-chat
root@08848d65c1e7:/app/src/Client# dotnet fable webpack -p
Fable (1.3.4) daemon started on port 61225
CWD: /app/src/Client
node "/app/node_modules/webpack/bin/webpack.js"
Bundling for development...
Parsing ./client.fsproj...
fable: Compiled client.fsproj
fable: Compiled App.fs
fable: Compiled State.fs
fable: Compiled ../../../root/.nuget/packages/fable.websockets.elmish/0.1.1/fable/src/Elmish.fs
fable: Compiled ../../../root/.nuget/packages/fable.elmish.debugger/1.0.1/fable/debugger.fs
fable: Compiled ../../../root/.nuget/packages/fable.elmish/1.0.1/fable/program.fs
fable: Compiled ../../../root/.nuget/packages/fable.elmish.browser/1.0.0/fable/navigation.fs
fable: Compiled ../../../root/.nuget/packages/fable.elmish.hmr/1.0.0/fable/hmr.fs
fable: Compiled NavMenu/View.fs
fable: Compiled Channel/View.fs
fable: Compiled ../../../root/.nuget/packages/fable.elmish.react/1.0.0/fable/react.fs
fable: Compiled ../../../root/.nuget/packages/fable.elmish/1.0.1/fable/cmd.fs
fable: Compiled Chat/Types.fs
fable: Compiled Router.fs
fable: Compiled Types.fs
fable: Compiled Info/View.fs
fable: Compiled ../../../root/.nuget/packages/fable.elmish.browser/1.0.0/fable/parser.fs
fable: Compiled Chat/State.fs
fable: Compiled ../../../root/.nuget/packages/fable.elmish.react/1.0.0/fable/common.fs
fable: Compiled Channel/Types.fs
fable: Compiled ../../../root/.nuget/packages/fable.elmish.debugger/1.0.1/fable/Fable.Import.RemoteDev.fs
fable: Compiled ../Shared/ChatProtocol.fs
fable: Compiled UserAvatar/View.fs
fable: Compiled ../../../root/.nuget/packages/fable.websockets.client/0.1.1/fable/src/Client.fs
fable: Compiled ../../../root/.nuget/packages/fable.websockets.client/0.1.1/Shared/Protocol.fs
fable: Compiled ../../../root/.nuget/packages/fable.websockets.client/0.1.1/Shared/Observables.fs
fable: Compiled ../../../root/.nuget/packages/fable.react/1.2.2/fable/Fable.Helpers.React.fs
fable: Compiled ../../../root/.nuget/packages/fable.elmish.browser/1.0.0/fable/prelude.fs
fable: Compiled Channel/State.fs
/app/node_modules/source-map/lib/source-map-consumer.js:704
      throw new Error('"' + aSource + '" is not in the SourceMap.');
      ^

Error: "/root/.nuget/packages/fable.elmish.browser/1.0.0/fable/prelude.fs" is not in the SourceMap.
    at SourceMapConsumer_sourceContentFor [as sourceContentFor] (/app/node_modules/source-map/lib/source-map-consumer.js:704:13)
    at /app/node_modules/source-map/lib/source-node.js:139:40
    at Array.forEach (native)
    at Function.SourceNode_fromStringWithSourceMap [as fromStringWithSourceMap] (/app/node_modules/source-map/lib/source-node.js:138:32)
    at SourceMapSource.node (/app/node_modules/webpack-sources/lib/SourceMapSource.js:39:21)
    at ReplaceSource.node (/app/node_modules/webpack-sources/lib/ReplaceSource.js:70:30)
    at CachedSource.node (/app/node_modules/webpack-sources/lib/CachedSource.js:18:24)
    at /app/node_modules/webpack-sources/lib/ConcatSource.js:37:50
    at Array.map (native)
    at ConcatSource.node (/app/node_modules/webpack-sources/lib/ConcatSource.js:36:63)
    at /app/node_modules/webpack-sources/lib/ConcatSource.js:37:50
    at Array.map (native)
    at ConcatSource.node (/app/node_modules/webpack-sources/lib/ConcatSource.js:36:63)
    at /app/node_modules/webpack-sources/lib/ConcatSource.js:37:50
    at Array.map (native)
    at ConcatSource.node (/app/node_modules/webpack-sources/lib/ConcatSource.js:36:63)
    at /app/node_modules/webpack-sources/lib/ConcatSource.js:37:50
    at Array.map (native)
    at ConcatSource.node (/app/node_modules/webpack-sources/lib/ConcatSource.js:36:63)
    at ConcatSource.proto.sourceAndMap (/app/node_modules/webpack-sources/lib/SourceAndMapMixin.js:30:18)
    at CachedSource.sourceAndMap (/app/node_modules/webpack-sources/lib/CachedSource.js:56:31)
    at getTaskForFile (/app/node_modules/webpack/lib/SourceMapDevToolPlugin.js:33:30)
    at chunk.files.forEach.file (/app/node_modules/webpack/lib/SourceMapDevToolPlugin.js:91:21)
    at Array.forEach (native)
    at /app/node_modules/webpack/lib/SourceMapDevToolPlugin.js:89:18
    at Array.forEach (native)
    at Compilation.<anonymous> (/app/node_modules/webpack/lib/SourceMapDevToolPlugin.js:88:12)
    at Compilation.applyPlugins1 (/app/node_modules/tapable/lib/Tapable.js:75:14)
    at self.applyPluginsAsync.err (/app/node_modules/webpack/lib/Compilation.js:670:11)
    at Compilation.applyPluginsAsyncSeries (/app/node_modules/tapable/lib/Tapable.js:195:46)
Closing Fable daemon...

[aolney]

@dustinlacewell-wk is /app/src/Client under /root? The workaround worked for me when my project folder was under /home/$USER

[dustinlacewell-wk]

OK this indeed worked.

[aolney]

This bit me again today 😜

[alfonsogarciacaro]

Maybe resolve: { symlinks: false } needs to be added to the Webpack config? fable-compiler/Fable#1490 (comment)

[aolney]

Thanks for that suggestion - it doesn't seem to help, but it did lead me to something else! I think I've figured out how to reproduce and repair the problem (but not the underlying cause).

Basically the problem seems to be created by passing in a hyphenated project name when using the template, e.g. awesome-test in:

dotnet new fable-elmish-react -n awesome-test -lang f#

Compiling in VsCode with dotnet fable npm-start will then yield the known error (#7):

ERROR in multi (webpack)-dev-server/client?http://0.0.0.0:8080 webpack/hot/dev-server ./src/awesome_test.fsproj
Module not found: Error: Can't resolve '/z/temp-junk/awesome-test/src/awesome_test.fsproj' in '/z/temp-junk/awesome-test'
 @ multi (webpack)-dev-server/client?http://0.0.0.0:8080 webpack/hot/dev-server ./src/awesome_test.fsproj

because the fsproj name has been made with an underscore instead of a hyphen. Fixing then by renaming awesome-test.fsproj to awesome_test.fsproj in VsCode, followed by a dotnet restore reproduces the throw new Error('"' + aSource + '" is not in the SourceMap.'); error.

I can "repair" the project by renaming all hypenated names and underscore names in all files to a variant with neither, e.g. awesome-test to awesometest, removing node_modules and src/obj, and then reinitializing everything.

The bug seems to possibly be a new variant of dotnet/templating#402 and not a bug in Elmish.

[alfonsogarciacaro]

Ah, yeah, it seems there's a note about that in the README but it's easy to miss. Quite annoying behavior of dotnet templates, they should fail instead of replacing characters silently :/

[aolney]

Agreed 👍 I saw that note in the README but thought just renaming the fsproj would repair. It's quite sneaky that it only repairs when you are on /home and that more drastic measures are needed when you are on another drive.