[GHC] #14676: GHCI doesn't recover from bad :add

[GHC]

#14676: GHCI doesn't recover from bad :add
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        Reporter:  Juzley            |                Owner:  Juzley
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  GHCi              |              Version:  8.2.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  Other             |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by Ben Gamari <ben@…>):

 In [changeset:"0bff9e677f0569bc8a7207c20cddddfd67e2448f/ghc"
 0bff9e67/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="0bff9e677f0569bc8a7207c20cddddfd67e2448f"
 Don't add targets that can't be found in GHCi

 When using the :add command in haxlsh/ghci, a module/file that can't
 be found is still added to the list of targets, resulting in an error
 message for the bad module/file for every subsequent usage of the
 command. The add command should verify that the module/file can be
 found before adding it to the list of targets.

 Also add a ":show targets" command to show the currently added list of
 commands, and an ":unadd" command to remove a target.

 Test Plan:
 Add a new GHCi testcase that checks that :add doesn't remember either
 files or modules that could not be found, and that both the new :show
 and :unadd commands work as expected.

 Reviewers: simonmar, bgamari

 Reviewed By: simonmar

 Subscribers: rwbarton, thomie, carter

 GHC Trac Issues: #14676

 Differential Revision: https://phabricator.haskell.org/D4321
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14676#comment:3>
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