users guide: Fix link to let generalization blog post

Fixes #17200.
31 jobs for master in 240 minutes and 28 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Lint
passed #159724
lint
lint-linters

00:00:14

passed #159727
lint
lint-submods-branch

00:00:15

passed #159725
lint
lint-testsuite

00:00:15

passed #159726
lint
typecheck-testsuite

00:00:13

 
  Build
passed #159729
x86_64-linux
hadrian-ghc-in-ghci

00:23:30

passed #159731
x86_64-linux
release-x86_64-linux-deb9-dwarf

01:54:43

failed #159730
x86_64-linux
validate-x86_64-linux-deb9-debug

01:44:42

passed #159728
x86_64-linux
validate-x86_64-linux-deb9-hadrian

03:59:50

 
  Full Build
skipped #159734
aarch64-linux allowed to fail
nightly-aarch64-linux-deb9
skipped #159736
x86_64-linux
nightly-i386-linux-deb9
skipped #159748
x86_64-windows allowed to fail
nightly-i386-windows
skipped #159745
x86_64-windows allowed to fail
nightly-i386-windows-hadrian
skipped #159742
x86_64-linux allowed to fail
nightly-x86_64-linux-alpine
skipped #159737
x86_64-linux
nightly-x86_64-linux-deb9
skipped #159740
x86_64-linux
nightly-x86_64-linux-deb9-integer-simple
skipped #159738
x86_64-linux
nightly-x86_64-linux-deb9-llvm
skipped #159747
x86_64-windows allowed to fail
nightly-x86_64-windows
skipped #159733
aarch64-linux allowed to fail
validate-aarch64-linux-deb9
skipped #159735
x86_64-linux
validate-i386-linux-deb9
skipped #159732
x86_64-darwin
validate-x86_64-darwin
skipped #159739
x86_64-linux
validate-x86_64-linux-deb9-integer-simple
skipped #159741
x86_64-linux
validate-x86_64-linux-deb9-unreg
skipped #159743
x86_64-linux
validate-x86_64-linux-fedora27
skipped #159746
x86_64-windows allowed to fail
validate-x86_64-windows
skipped #159744
x86_64-windows allowed to fail
validate-x86_64-windows-hadrian
 
  Cleanup
passed #159749
x86_64-darwin
cleanup-darwin

00:00:04

 
  Packaging
skipped #159750
x86_64-linux allowed to fail
doc-tarball
 
  Testing
skipped #159751
x86_64-linux allowed to fail manual
hackage
skipped #159752
x86_64-linux
nightly-hackage
skipped #159753
x86_64-linux
perf-nofib
 
  Deploy
skipped #159754
x86_64-linux allowed to fail
pages
 
Name Stage Failure
failed
validate-x86_64-linux-deb9-debug Build
$ cp -Rf $HOME/.cabal cabal-cache
Uploading artifacts...
ghc-*.tar.xz: found 1 matching files
junit.xml: found 1 matching files

Uploading artifacts to coordinator... ok
id=159730 responseStatus=201 Created token=eTDKnH_w
Uploading artifacts...
junit.xml: found 1 matching files

Uploading artifacts to coordinator... ok
id=159730 responseStatus=201 Created token=eTDKnH_w
ERROR: Job failed: exit code 1