Add changelog for haskell#7413 (Fix instantiating an indefinite Backp…

…ack from Hackage with an inplace package)

changelog.d/pr-7413

@@ -0,0 +1,13 @@
+synopsis: Fix instantiating an indefinite Backpack from Hackage with an inplace package
+packages: cabal-install
+prs: #7413
+issues: #6835
+description: {
+
+Previously, cabal-install would always attempt to put instantiations of indefinite packages from Hackage in
+the global package store, even if they were instantiated with inplace packages.  This would not work
+and GHC would complain about packages being missing from the package database.  We have fixed the
+instantiation algorithm to correctly inplace packages in these situations, removing one of the last
+blockers to widespread use of Backpack packages on Hackage.
+
+}