bitbake: fetch2/cooker: Fix source revision handling with floating upstreams

Where a git url uses a tag instead of a full source revision, breakage
can currently occur in builds. Issues include:

* the revision being looked up in multiple tasks (fetch and unpack)
* the risk a different revision may be obtained in those tasks
* that some tasks may not be allowed to access the network
* that a revision may not be consistent throughout a given build
* rerunning a specific task may given inconsistent results

To fix this, stop the workers from cleaning out the source revision store. This
should only be done in the cooker itself (based on current policy).

Also, where the code "sees" an upstream access, mark the recipe as not to be
cached. The reparse re-triggers the upstream lookup by the server.

Add a test to ensure that if get_srcrev isn't called, the user is told they're
using a configuration that is known to break.

(Bitbake rev: 4b5eed1626709ef3dc06b32fd55d40a2a6edd179)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 7 insertions, 0 deletions

diff --git a/bitbake/lib/bb/fetch2/__init__.py b/bitbake/lib/bb/fetch2/__init__.py
index 28a3e54c7f..d099cd1092 100644
--- a/bitbake/lib/bb/fetch2/__init__.py
+++ b/bitbake/lib/bb/fetch2/__init__.py
@@ -765,6 +765,7 @@ def get_srcrev(d, method_name='sortable_revision'):
     that fetcher provides a method with the given name and the same signature as sortable_revision.
     """
 
+    d.setVar("__BBSEENSRCREV", "1")
     recursion = d.getVar("__BBINSRCREV")
     if recursion:
         raise FetchError("There are recursive references in fetcher variables, likely through SRC_URI")
diff --git a/bitbake/lib/bb/fetch2/git.py b/bitbake/lib/bb/fetch2/git.py
index 30da8e95b7..836ef1c49a 100644
--- a/bitbake/lib/bb/fetch2/git.py
+++ b/bitbake/lib/bb/fetch2/git.py
@@ -727,6 +727,12 @@ class Git(FetchMethod):
         """
         Compute the HEAD revision for the url
         """
+        if not d.getVar("__BBSEENSRCREV"):
+            raise bb.fetch2.FetchError("Recipe uses a floating tag/branch without a fixed SRCREV yet doesn't call bb.fetch2.get_srcrev() (use SRCPV in PV for OE).")
+
+        # Ensure we mark as not cached
+        bb.fetch2.get_autorev(d)
+
         output = self._lsremote(ud, d, "")
         # Tags of the form ^{} may not work, need to fallback to other form
         if ud.unresolvedrev[name][:5] == "refs/" or ud.usehead: