diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index a4d545e0f..3ac18a420 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -16,7 +16,7 @@ jobs:
       - task: CacheBeta@1
         displayName: 'cache Nim binaries'
         inputs:
-          key: NimBinaries | $(Agent.OS) | $(PLATFORM) | "$(Build.SourceBranchName)" | "v4"
+          key: NimBinaries | $(Agent.OS) | $(PLATFORM) | "$(Build.SourceBranchName)" | "v7"
           path: NimBinaries
 
       - task: CacheBeta@1
diff --git a/config.nims b/config.nims
index d42a604df..fa16d8772 100644
--- a/config.nims
+++ b/config.nims
@@ -44,3 +44,10 @@ if not defined(macosx):
 # libnimbus.so needs position-independent code
 switch("passC", "-fPIC")
 
+# The compiler doth protest too much, methinks, about all these cases where it can't
+# do its (N)RVO pass: https://github.com/nim-lang/RFCs/issues/230
+switch("warning", "ObservableStores:off")
+
+# Too many false positives for "Warning: method has lock level <unknown>, but another method has 0 [LockLevel]"
+switch("warning", "LockLevel:off")
+
diff --git a/vendor/nimbus-build-system b/vendor/nimbus-build-system
index bb82ba898..ae49e03af 160000
--- a/vendor/nimbus-build-system
+++ b/vendor/nimbus-build-system
@@ -1 +1 @@
-Subproject commit bb82ba89841e625db9a998be4339f090ff47976d
+Subproject commit ae49e03af6f36393eb7e0fc02c1c47df42efd2de