Error installing dependencies with new build in windows: "you don't have permission to modify this file"

[jneira]

Hi, installing dhall-haskell in windows i've usually got errors, not always in the same dependency:

eta-pkg: D:\sd\eta-0.7.2.2\package.db\package.cache: you don't have permission t
o modify this file
....
Failed to build parsec-3.1.13.0. The failure occurred during the final install
step.
Build log (
C:\Users\user\AppData\Roaming\etlas\logs\eta-0.7.2.2\parsec-3.1.13.0-ef999ca9e1d0
e8852b1c568fd086cdbe3a1ad978.log
):
Installing library in D:\sd\eta-0.7.2.2\incoming\new-7972\sd\eta-0.7.2.2\parsec-
3.1.13.0-ef999ca9e1d0e8852b1c568fd086cdbe3a1ad978\lib
 [K [1m [32m✓ Successfully built 25 modules. Mission Accomplished! [0mm [0m0m

 [0m
etlas: Failed to build parsec-3.1.13.0 (which is required by exe:dhall-hash
from dhall-1.14.0, exe:dhall-format from dhall-1.14.0 and others). See the
build log above for details.

Not sure if the cause is the long paths issue of windows or some problem with locks...
Rerunning the etlas build the error is gone. Maybe related with haskell/cabal#4005 (fixed)

[rahulmutt]

Definitely sounds like a locking problem. We should implement the fix mentioned in the linked issue.