Flow: Fatal error: exception Invalid_argument("String.sub / Bytes.sub")

[kimmobrunfeldt]

When running flow, I get a fatal error:

Fatal error: exception Invalid_argument("String.sub / Bytes.sub")

I have an empty .flowconfig created with flow init. I installed flow via npm install flow-bin, but that downloads the released binary so I assumed it makes no difference.

Versions:
OS X 10.10.5
Flow: OS X Binaries: v0.19.0/flow-osx-v0.19.0.zip
npm 2.14.2
node v4.0.0

[danvk]

I'm also seeing this on my project.

OS X 10.10.5
Flow 0.19.0
npm 3.3.9
node v5.0.0

[mroch]

looking at the places we call String.sub, it's most likely while trying to print an error. can you try with --old-output-format? that'll help figure out what the error struct looks like so we can repro with the new printer.

[danvk]

$ flow check --old-output-format

/Users/danvk/github/pileup.js/node_modules/npmconf/test/fixtures/package.json:1:3,2: Unexpected end of input

Found 1 error

[danvk]

Adding .*node_modules/npmconf.* to the ignore section of my .flowconfig made the error go away.

[mroch]

hrm, that's an empty file. we have a unit test for that, I think because of this exact npm module, since it has invalid files in its tests... I'll try to repro.

[mroch]

our unit tests run with --old-output-format so they pass... but it repros if you do flow check tests/node_tests/ without --old-output-format.

[kimmobrunfeldt]

I tried it with the --old-output-format as you adviced. I get the same error as @danvk but from a different module apparently:

/My/Project/Path/node_modules/david/node_modules/npm/test/fixtures/config/package.json:1:3,2: Unexpected end of input

[mroch]

found the problem, fix incoming. ignoring .*node_modules/npm/test/.* is not a bad idea anyway, and should work around this in the meantime.

[kimmobrunfeldt]

That was fast, thanks! :)

[danvk]

Thanks @mroch. Does this merit a 0.19.1 bugfix release?

[gabelevi]

Yep! We're cherry picking the fix into a 0.19.1 release. First time doing it this way, so hopefully we don't ruin everything!

[gabelevi]

Ok 0.19.1 is tagged and released.

• flow-bin is published
• homebrew PR is out
• opam PR is out

Thanks for the error report, thanks for using flow, and thanks for your patience!

[bcowgill]

I am getting this same error and not seeing line numbers when I use old output format so rather tricky fixing things.

Flow, a static type checker for JavaScript, version 0.22.1
Linux worksharexps-XPS-15-9530 3.19.0-43-generic #49-Ubuntu SMP Sun Dec 27 19:43:07 UTC 2015 x86_64 x86_64 x86_64 GNU/Linux

NODE_DEBUG=* ./node_modules/.bin/flow
Fatal error: exception Invalid_argument("String.sub / Bytes.sub")
$ NODE_DEBUG=* ./node_modules/.bin/flow --old-output-format

lib/support.js: return
Missing annotation

support.js:99:4,4: return
Missing annotation

support.js: return
Missing annotation

lib/support.js: return
Missing annotation

lib/support.js: return
Missing annotation

lib/support.js: return
Missing annotation

Found 6 errors

[bcowgill]

After some investigation it seems the flow parser will choke on this:
function x() //: function
{
}

but not
function x() /*: function */
{
}

my bad assumption about how the annotation comments could be formatted.

[echenley]

Just had this issue in Flow v0.47. Adding .*/node_modules/npm/test/.* to the [ignore] section of .flowconfig resolved it.

[andreiglingeanu]

Same, I'm on 0.59.0.

[toddmedema]

Same error on 1.4.0, but none of these [ignore]s fixed it and the --old-output-format is now disabled. Is there any other way I can get a more useful error out of this? (eventually found the problem folder (something in node_modules) by ignoring everything and slowly adding them back, but it would have been great to have a useful error from the start...)

[rodrigopr]

got same error on latest flow version (0.66.0)

Unhandled exception: Invalid_argument("String.sub / Bytes.sub")
Raised at file "pervasives.ml", line 33, characters 20-45
Called from file "string.ml", line 47, characters 2-23
Called from file "src/common/errors/errors.ml", line 2045, characters 44-70
Called from file "list.ml", line 96, characters 24-34
Called from file "src/common/errors/errors.ml", line 2014, characters 46-1023
Called from file "list.ml", line 96, characters 24-34
Called from file "src/common/errors/errors.ml", line 2007, characters 32-1023
Called from file "map.ml", line 286, characters 19-24
Called from file "map.ml", line 285, characters 19-27
Called from file "src/common/errors/errors.ml", line 1999, characters 22-1023
Called from file "src/common/errors/errors.ml", line 2400, characters 8-170
Called from file "src/common/errors/errors.ml", line 2570, characters 12-320
Called from file "list.ml", line 85, characters 12-15
Called from file "src/common/errors/errors.ml", line 2582, characters 8-62
Called from file "src/flow.ml", line 82, characters 6-34

Managed to find the source of the errors with flow --json --pretty (cc @toddmedema)

[caoilte]

Just encountered this problem. Went away after I forced the server to reinitialise.

[toddmedema]

@caoilte I've also been getting a surprising number of errors about node_modules that are fixed with a server restart. A bit disappointed that that's even a problem... seems like a pretty big bug with the server system.

[Hawkz69]

runkillall flow
then and run flow.