after updating to the latest version, I still got the error:

[2015-07-24 23:11:10] EXCEPTION: (ConduitClientException) ERR-CONDUIT-CORE: Parameter 'line' has invalid type. Expected type 'optional int', got type 'string'. at [<phutil>/src/conduit/ConduitFuture.php:58]
affogatolinter(), arcanist(head=master, ref.master=999eb9376568), owners(), phutil(head=master, ref.master=aa6cd8f7e5e5)

#0 <#2> ConduitFuture::didReceiveResult(array) called at [<phutil>/src/future/FutureProxy.php:58]
#1 <#2> FutureProxy::getResult() called at [<phutil>/src/future/FutureProxy.php:35]
#2 <#2> FutureProxy::resolve() called at [<arcanist>/src/workflow/ArcanistDiffWorkflow.php:2786]
#3 phlog(ConduitClientException) called at [<arcanist>/src/workflow/ArcanistDiffWorkflow.php:2792]
#4 ArcanistDiffWorkflow::updateAutotargets(string, integer) called at [<arcanist>/src/workflow/ArcanistDiffWorkflow.php:530]
#5 ArcanistDiffWorkflow::run() called at [<arcanist>/scripts/arcanist.php:382]

Any ideas?

Is arc up to date? This change affects Arcanist, not Phabricator.

Yes, arc up to date:

On the client:
EX10301:pinboard nickz$ arc --version
arcanist 5fcf7b5a3b9ebbb42130b25f165283dbe2476f0c (24 Jul 2015)
libphutil aa6cd8f7e5e5e637dcfcb8417fbc343b45820c93 (8 Jul 2015)

On the server:
[root@phabulous006:/mnt/arcanist (master)]# git log -1
commit 5fcf7b5a3b9ebbb42130b25f165283dbe2476f0c
Author: Lukas Sparrow <lukas.sparrow@gmail.com>
Date: Fri Jul 24 05:11:32 2015 -0700

Can you show me the complete output on the client with --trace?

EX10301:pinboard nickz$ arc diff --trace
libphutil loaded from '/Users/nickz/Arcanist/libphutil/src'.
arcanist loaded from '/Users/nickz/Arcanist/arcanist/src'.
Config: Reading user configuration file "/Users/nickz/.arcrc"...
Config: Did not find system configuration at "/etc/arcconfig".
Working Copy: Reading .arcconfig from "/Users/nickz/code/pinboard/.arcconfig".
Working Copy: Path "/Users/nickz/code/pinboard" is part of git working copy "/Users/nickz/code/pinboard".
Working Copy: Project root is at "/Users/nickz/code/pinboard".
Config: Did not find local configuration at "/Users/nickz/code/pinboard/.git/arc/config".
Loading phutil library from '/Users/nickz/code/pinboard/.phabricator-libs/affogatolinter'...
Loading phutil library from '/Users/nickz/code/pinboard/.phabricator-libs/owners'...

[0] <conduit> conduit.connect() <bytes = 455>
[1] <http> https://phabricator.pinadmin.com/api/conduit.connect

<<< [1] <http> 1,675,525 us
<<< [0] <conduit> 1,675,896 us

[2] <exec> $ git diff --no-ext-diff --no-textconv --raw 'HEAD' --
[3] <exec> $ git ls-files --others --exclude-standard

<<< [2] <exec> 139,713 us
<<< [3] <exec> 138,967 us

[4] <exec> $ git diff-files --name-only

<<< [4] <exec> 69,617 us

[5] <event> diff.didCollectChanges <listeners = 0>

<<< [5] <event> 54 us

[6] <exec> $ git rev-parse --verify HEAD^

<<< [6] <exec> 29,763 us

[7] <exec> $ git merge-base 'origin/master' HEAD

<<< [7] <exec> 31,620 us

[8] <exec> $ git rev-parse 'HEAD'

<<< [8] <exec> 28,088 us

[9] <exec> $ git log --first-parent --format=medium '955511af274213958dceec8da321a786467ed6bc'..'cd5209c7bf769de9e293afa3b8a90327a28a3d48'

<<< [9] <exec> 31,014 us

[10] <conduit> differential.query() <bytes = 291>
[11] <http> https://phabricator.pinadmin.com/api/differential.query

<<< [11] <http> 1,275,340 us
<<< [10] <conduit> 1,275,577 us

[12] <exec> $ git rev-parse --git-dir

<<< [12] <exec> 6,059 us
You have a saved revision message in '.git/arc/create-message'.
Message begins:

just a test, don't merge

You can use this message, or discard it.

Do you want to use this message? [Y/n]

[13] <exec> $ git log 'cd5209c7bf769de9e293afa3b8a90327a28a3d48' --not '955511af274213958dceec8da321a786467ed6bc' --format='%H%x01%T%x01%P%x01%at%x01%an%x01%aE%x01%s%x01%s%n%n%b%x02' --

<<< [13] <exec> 33,376 us

[14] <conduit> differential.parsecommitmessage() <bytes = 348>
[15] <http> https://phabricator.pinadmin.com/api/differential.parsecommitmessage

<<< [15] <http> 2,227,047 us
<<< [14] <conduit> 2,227,267 us

[16] <conduit> differential.parsecommitmessage() <bytes = 325>
[17] <http> https://phabricator.pinadmin.com/api/differential.parsecommitmessage

<<< [17] <http> 1,406,056 us
<<< [16] <conduit> 1,406,323 us

[18] <event> diff.willBuildMessage <listeners = 0>

<<< [18] <event> 75 us

[19] <exec> $ git branch --no-color

<<< [19] <exec> 31,748 us

[20] <exec> $ vim '/var/folders/n0/hrlsr3695dv1d116vhl2lt3c0000gn/T/edit.62ovzr9g4zcw0gkk/new-commit'

<<< [20] <exec> 2,525,912 us

[21] <conduit> differential.parsecommitmessage() <bytes = 473>
[22] <http> https://phabricator.pinadmin.com/api/differential.parsecommitmessage

<<< [22] <http> 1,377,830 us
<<< [21] <conduit> 1,378,095 us

[23] <conduit> differential.query() <bytes = 187>
[24] <http> https://phabricator.pinadmin.com/api/differential.query

You have not specified any reviewers. Continue anyway? [y/N] y

<<< [24] <http> 1,857,573 us
<<< [23] <conduit> 1,857,884 us

[25] <event> diff.didBuildMessage <listeners = 0>

<<< [25] <event> 87 us

[26] <conduit> differential.getcommitmessage() <bytes = 239>
[27] <http> https://phabricator.pinadmin.com/api/differential.getcommitmessage

<<< [27] <http> 1,367,975 us
<<< [26] <conduit> 1,368,255 us

[28] <conduit> differential.parsecommitmessage() <bytes = 414>
[29] <http> https://phabricator.pinadmin.com/api/differential.parsecommitmessage

<<< [29] <http> 4,125,328 us
<<< [28] <conduit> 4,125,548 us

[30] <exec> $ git log --first-parent --format=medium '955511af274213958dceec8da321a786467ed6bc'..'cd5209c7bf769de9e293afa3b8a90327a28a3d48'

<<< [30] <exec> 33,318 us

[31] <conduit> differential.querydiffs() <bytes = 195>
[32] <http> https://phabricator.pinadmin.com/api/differential.querydiffs

<<< [32] <http> 1,401,574 us
<<< [31] <conduit> 1,401,763 us

[33] <exec> $ vim '/var/folders/n0/hrlsr3695dv1d116vhl2lt3c0000gn/T/edit.1mtz9p2f7rgg44ko/differential-update-comments'

<<< [33] <exec> 11,757,111 us
Linting...

[34] <exec> $ git rev-parse 'HEAD'

<<< [34] <exec> 29,921 us

[35] <exec> $ git merge-base '955511af274213958dceec8da321a786467ed6bc' 'cd5209c7bf769de9e293afa3b8a90327a28a3d48'

<<< [35] <exec> 33,030 us

[36] <exec> $ git diff --no-ext-diff --no-textconv --raw '955511af274213958dceec8da321a786467ed6bc' --

<<< [36] <exec> 129,290 us

[37] <exec> $ git diff --no-ext-diff --no-textconv --no-color --src-prefix=a/ --dst-prefix=b/ -U32767 -M -C '955511af274213958dceec8da321a786467ed6bc' --

<<< [37] <exec> 136,118 us
Examining paths for linter 'flake8'.
Found 1 matching paths for linter 'flake8'.

[38] <exec> $ which 'flake8'

<<< [38] <exec> 4,529 us

[39] <exec> $ which 'flake8'

<<< [39] <exec> 2,919 us

[40] <exec> $ 'flake8' --version

<<< [40] <exec> 513,352 us

[41] <lint> Flake8 <paths = 1>
[42] <exec> $ which 'flake8'

<<< [42] <exec> 3,075 us

[43] <exec> $ 'flake8' '/Users/nickz/code/pinboard/urls.py'

<<< [41] <lint> 4,176 us

[44] <lint> Flake8 <paths = 1>

<<< [43] <exec> 180,918 us
<<< [44] <lint> 181,406 us

Lint for urls.py:

Error  (E265) flake8 1
 block comment should start with '# '

            1 from django.conf.urls import include, patterns
            2 
 >>>        3 ## #Default handlers for errors
            4 handler500 = 'django.views.defaults.server_error'
            5 handler404 = 'django.views.defaults.page_not_found'
            6 handler403 = 'django.views.defaults.permission_denied'

LINT ERRORS Lint raised errors!

Lint issued unresolved errors! Provide explanation to continue or press Enter
to abort.

[45] <exec> $ bash -c 'true'

<<< [45] <exec> 3,746 us

Explanation: test

Running unit tests...
UNIT OKAY No unit test failures.

[46] <exec> $ git rev-parse 'HEAD'

<<< [46] <exec> 30,805 us

[47] <exec> $ git merge-base '955511af274213958dceec8da321a786467ed6bc' 'cd5209c7bf769de9e293afa3b8a90327a28a3d48'

<<< [47] <exec> 32,943 us

[48] <exec> $ git diff --no-ext-diff --no-textconv --no-color --src-prefix=a/ --dst-prefix=b/ -U32767 -M -C '955511af274213958dceec8da321a786467ed6bc' 'cd5209c7bf769de9e293afa3b8a90327a28a3d48' --

<<< [48] <exec> 38,928 us

[49] <exec> $ git rev-parse '955511af274213958dceec8da321a786467ed6bc'

<<< [49] <exec> 33,827 us

[50] <exec> $ git branch --no-color

<<< [50] <exec> 29,987 us

[51] <exec> $ git log --format=medium -n16 '955511af274213958dceec8da321a786467ed6bc'

<<< [51] <exec> 34,795 us

[52] <conduit> repository.query() <bytes = 195>
[53] <http> https://phabricator.pinadmin.com/api/repository.query

<<< [53] <http> 1,772,772 us
<<< [52] <conduit> 1,773,000 us

[54] <conduit> differential.creatediff() <bytes = 1722>
[55] <http> https://phabricator.pinadmin.com/api/differential.creatediff

<<< [55] <http> 1,393,777 us
<<< [54] <conduit> 1,393,959 us

[56] <event> diff.wasCreated <listeners = 0>

<<< [56] <event> 46 us
SKIP STAGING No staging area is configured for this repository.

[57] <conduit> harbormaster.queryautotargets() <bytes = 288>
[58] <http> https://phabricator.pinadmin.com/api/harbormaster.queryautotargets

<<< [58] <http> 1,454,133 us
<<< [57] <conduit> 1,454,360 us

[59] <conduit> harbormaster.sendmessage() <bytes = 553>
[60] <http> https://phabricator.pinadmin.com/api/harbormaster.sendmessage
[61] <conduit> harbormaster.sendmessage() <bytes = 272>
[62] <http> https://phabricator.pinadmin.com/api/harbormaster.sendmessage

<<< [60] <http> 1,263,273 us
<<< [59] <conduit> 1,274,636 us
[2015-07-26 05:32:42] EXCEPTION: (ConduitClientException) ERR-CONDUIT-CORE: Parameter 'char' has invalid type. Expected type 'optional int', got type 'string'. at [<phutil>/src/conduit/ConduitFuture.php:58]
affogatolinter(), arcanist(head=master, ref.master=5fcf7b5a3b9e), owners(), phutil(head=master, ref.master=aa6cd8f7e5e5)

#0 <#2> ConduitFuture::didReceiveResult(array) called at [<phutil>/src/future/FutureProxy.php:58]
#1 <#2> FutureProxy::getResult() called at [<phutil>/src/future/FutureProxy.php:35]
#2 <#2> FutureProxy::resolve() called at [<arcanist>/src/workflow/ArcanistDiffWorkflow.php:2786]
#3 phlog(ConduitClientException) called at [<arcanist>/src/workflow/ArcanistDiffWorkflow.php:2792]
#4 ArcanistDiffWorkflow::updateAutotargets(string, integer) called at [<arcanist>/src/workflow/ArcanistDiffWorkflow.php:530]
#5 ArcanistDiffWorkflow::run() called at [<arcanist>/scripts/arcanist.php:382]

[63] <conduit> differential.setdiffproperty() <bytes = 263>
[64] <http> https://phabricator.pinadmin.com/api/differential.setdiffproperty
[65] <conduit> differential.setdiffproperty() <bytes = 728>
[66] <http> https://phabricator.pinadmin.com/api/differential.setdiffproperty
[67] <exec> $ git log 'cd5209c7bf769de9e293afa3b8a90327a28a3d48' --not '955511af274213958dceec8da321a786467ed6bc' --format='%H%x01%T%x01%P%x01%at%x01%an%x01%aE%x01%s%x01%s%n%n%b%x02' --

<<< [67] <exec> 30,931 us

[68] <conduit> differential.setdiffproperty() <bytes = 1655>
[69] <http> https://phabricator.pinadmin.com/api/differential.setdiffproperty

<<< [64] <http> 1,229,272 us
<<< [63] <conduit> 1,229,667 us
<<< [69] <http> 1,804,304 us
<<< [68] <conduit> 1,804,601 us
<<< [66] <http> 1,846,618 us
<<< [65] <conduit> 1,846,869 us

[70] <conduit> differential.updaterevision() <bytes = 447>
[71] <http> https://phabricator.pinadmin.com/api/differential.updaterevision

<<< [71] <http> 1,927,964 us
<<< [70] <conduit> 1,928,138 us
Updated an existing Differential revision:

Revision URI: https://phabricator.pinadmin.com/D38076

Included changes:

M       urls.py

Aha! That's a different error:

[2015-07-26 05:32:42] EXCEPTION: (ConduitClientException) ERR-CONDUIT-CORE: Parameter 'char' has invalid type. Expected type 'optional int', got type 'string'. at [<phutil>/src/conduit/ConduitFuture.php:58]

Note char vs line. I'll fix this.

Good catch! Thanks!!!