frasertweedale

{-# LANGUAGE KindSignatures #-}

module Workflow where

import Data.Bool (bool)


data Workflow a r
  = Decision a (Workflow a r) (Workflow a r)
  | Guard a (Workflow a r)

frasertweedale

#!/usr/bin/python3

import os
from dns import resolver
from ipalib import api
from ipapython import dnsutil

certbot_domain = os.environ['CERTBOT_DOMAIN']
certbot_validation = os.environ['CERTBOT_VALIDATION']
if 'CERTBOT_AUTH_OUTPUT' in os.environ:

frasertweedale

Conferences

• YOW! Lambda Jam 2020 cancelled
  • https://yowconference.com/lambdajam/
  • Low submissions + low sponsorship + COVID-19 = :(
• Who wants to organise a conf?

frasertweedale

    message round trip with From header:                  FAIL (47.81s)
        ✗ message round trip with From header failed at tests/Message.hs:106:3
          after 866 tests and 69 shrinks.
         
              ┏━━ tests/Message.hs ━━━
          100 ┃ prop_messageFromRoundTrip :: Property
          101 ┃ prop_messageFromRoundTrip = property $ do
          102 ┃   from <- forAll genMailbox
              ┃   │ Mailbox (Just "\r\n") (AddrSpec "!" (DomainDotAtom ("!" :| [])))
          103 ┃   let

frasertweedale

Conferences

YOW! Lambda Jam 2020

• https://yowconference.com/lambdajam/
• Brisbane (BCEC) Wed 6..Fri 8 May
• CFP open until 23 Feb: https://yowconference.com/cfps/
• We will mentor speakers / help you craft a compelling proposal.

frasertweedale

Notes about a very hard to debug bug:

Eventually I deduced that it was lack of thread safety in talloc causing corruption and (most of the time) an abort() when talloc itself detected the corruption.

So, I created pthread mutexs around all operations that might do talloc things. Including routines called from finalisers.

This resulted in instant deadlocks. Why? forkIO was being used, instead of forkOS to create bound threads. Because Haskell execution capability can move among OS threads,

frasertweedale

dn: cn=issuername,cn=index,cn=ipaca,cn=ldbm database, cn=plugins, cn=config
objectClass: top
objectClass: nsIndex
nsindexType: eq
nsindexType: pres
nsindexType: sub
nsSystemindex: false
cn: issuername

frasertweedale

Installing a library explicitly via cabal v2-install lib:blah installs it in the package-db and exposes it. If there are multiple exposed instances of a library available, GHC chooses an unspecified instance (ref). Therefore it is sometimes necessary to manually hide or unregister conflicting versions of packages.

Look for library package-id in cabal install output:

Installing library in /home/ftweedal/.cabal/store/ghc-8.4.4/incoming/new-8790/home/ftweedal/.cabal/store/
ghc-8.4.4/purebred-icu-0.1.0.0-c850b6a0c804167cfc4542bce128a8714de643dcfd6a7114ff42f7e11986c81d/lib

frasertweedale

[T470s:~/dev/hs-dynload-experiment] ftweedal% ghc -c Profile.hs             
Loaded package environment from /home/ftweedal/dev/hs-dynload-experiment/.ghc.environment.x86_64-linux-8.4.4

[T470s:~/dev/hs-dynload-experiment] ftweedal% nm Profile.o
                 U base_GHCziBase_zpzp_closure
                 U ghczmprim_GHCziTypes_Module_con_info
                 U ghczmprim_GHCziTypes_TrNameS_con_info
0000000000000000 D Profile_resource_closure
0000000000000020 T Profile_resource_info
0000000000000030 D Profile_zdtrModule_closure

frasertweedale

-- Copyright (C) 2019  Fraser Tweedale
--
-- This program is free software: you can redistribute it and/or modify
-- it under the terms of the GNU Affero General Public License as published by
-- the Free Software Foundation, either version 3 of the License, or
-- (at your option) any later version.
--
-- This program is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the