Broken symlinks in lndir build tree

I routinely create separate build trees using lndir (per wiki:WorkingConventions/Git#Creatingabuildtreewithlndir). However it seems this is currently broken by the code to copy fs.{c,h} to various places in ./configure (see D4416):

$ mkdir ghc-validate
$ cd ghc-validate
$ lndir ../ghc
$ ln -s ../ghc/.git
$ ./boot
[...]
$ ./configure
[...]
$ find . -name "fs.*" | xargs file
./rts/fs.c:                    broken symbolic link to ../../../ghc/utils/fs/fs.c
./rts/fs.h:                    broken symbolic link to ../../../ghc/utils/fs/fs.h
./utils/fs/fs.c:               symbolic link to ../../../ghc/utils/fs/fs.c
./utils/fs/fs.h:               symbolic link to ../../../ghc/utils/fs/fs.h
./utils/unlit/fs.c:            symbolic link to ../../../ghc/utils/fs/fs.c
./utils/unlit/fs.h:            symbolic link to ../../../ghc/utils/fs/fs.h
./utils/lndir/fs.c:            symbolic link to ../../../ghc/utils/fs/fs.c
./utils/lndir/fs.h:            symbolic link to ../../../ghc/utils/fs/fs.h
./libraries/base/include/fs.h: broken symbolic link to ../../../ghc/utils/fs/fs.h
./libraries/base/cbits/fs.c:   broken symbolic link to ../../../ghc/utils/fs/fs.c

This can be fixed by manually correcting the symlinks, but it is a bit of pain, especially for ./validate.

ln -fs ../../ghc/utils/fs/fs.c rts/fs.c
ln -fs ../../ghc/utils/fs/fs.h rts/fs.h
ln -fs ../../../../ghc/utils/fs/fs.c libraries/base/include/fs.c
ln -fs ../../../../ghc/utils/fs/fs.h libraries/base/include/fs.h
ln -fs ../../../../ghc/utils/fs/fs.c libraries/base/cbits/fs.c

Trac metadata

Trac field	Value
Version	8.5
Type	Bug
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Build System
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture