diff --git a/doc/manual/bugs.xml b/doc/manual/bugs.xml
index d21603559..aa87e4b57 100644
--- a/doc/manual/bugs.xml
+++ b/doc/manual/bugs.xml
@@ -15,18 +15,6 @@ generation 43 is created which is a descendant of 39, not 42. So a
rollback from 43 ought to go back to 39. This is not currently
implemented; generations form a linear sequence.
-Build management. In principle it
-is already possible to do build management using Nix (by writing
-builders that perform appropriate build steps), but the Nix expression
-language is not yet powerful enough to make this pleasant (?). The
-language should be extended with features from the Maak build
-manager. Another interesting idea is to write a
-make implementation that uses Nix as a back-end to
-support legacy
-build files.
-
For security, nix-push manifests
should be digitally signed, and nix-pull should
verify the signatures. The actual NAR archives in the cache do not
diff --git a/doc/manual/nix-store.xml b/doc/manual/nix-store.xml
index 0a7ecdf06..5edc1cdaa 100644
--- a/doc/manual/nix-store.xml
+++ b/doc/manual/nix-store.xml
@@ -681,7 +681,7 @@ deployment.
-Operation
+Operation Synopsis
diff --git a/doc/manual/troubleshooting.xml b/doc/manual/troubleshooting.xml
index 9a61205b7..c0add7fdd 100644
--- a/doc/manual/troubleshooting.xml
+++ b/doc/manual/troubleshooting.xml
@@ -33,6 +33,50 @@ $ rm __db.00*
+Berkeley DB gives weird error messages
+
+Symptom: you get error messages such as
+
+
+Berkeley DB message: Finding last valid log LSN: file: 1 offset 28
+Berkeley DB error: file validpaths (meta pgno = 0) has LSN [483][34721].
+Berkeley DB error: end of log is [1][28]
+Berkeley DB error: /nix/var/nix/db/validpaths: unexpected file type or format
+
+or other weird Berkeley DB errors, and they don’t away (i.e.,
+automatic recovery doesn’t work). This may be the case after a system crash.
+
+Solution: first try to run db_recover and
+then nix-store
+--verify:
+
+
+$ db_recover -h /nix/var/nix/db
+$ nix-store --verify
+
+(Make sure that you have the right version of
+db_recover, namely, Berkeley DB 4.4 for Nix 0.10,
+and 4.5 for Nix 0.11.)
+
+If that doesn’t work, it’s time to bring out the big guns:
+
+
+$ cd /nix/var/nix
+$ cp -pr db db-backup (making a backup just in case)
+$ cd db
+$ rm __db.* log* (removing the Berkeley DB environment)
+$ mkdir tmp
+$ for i in *; do db_dump $i | (cd tmp && db_load $i); done
+(ignore error messages about non-database files like “reserved”)
+$ mv tmp/* .
+$ nix-store --verify
+
+
+
+
+
+
+
Collisions in nix-envSymptom: when installing or upgrading, you get an error message such as