try updating dpkg db after restoring apt sources, this way the live system will have...

diff --git a/modules/approx.mk b/modules/approx.mk
index 471cf31775277e12f8eaac67465dbf5b05399a5a..1c2e9a9112c963847c27daf6c5470cf6e9229531 100644 (file)
--- a/modules/approx.mk
+++ b/modules/approx.mk
@@ -27,3 +27,4 @@ endif
 _config: _approx_restore_sources
 _approx_restore_sources: ${CFGROOT}
        printf '%s\n' "$${approx_original_sources}" >"$${CFGROOT}/etc/apt/sources.list"
+       -chroot "$${CFGROOT}" apt-get update