Fix "task failed, build succeeded" situation in osbs2

It can happen that a brew task fails, but brew considers the build to be
good. This commit moves the calculation of the resulting nvr forward,
and upon task failure, asks brew if the nvr has been built
successfully.

doozerlib/osbs2_builder.py

@@ -60,6 +60,7 @@ async def build(self, image: "image.ImageMetadata", profile: Dict, retries: int
 
         error = None
         message = None
+        nvr = f"{image.get_component_name()}-{dg.org_version}-{dg.org_release}"
         for attempt in range(retries):
             logger.info("Build attempt %s/%s", attempt + 1, retries)
             try:
@@ -83,22 +84,12 @@ async def build(self, image: "image.ImageMetadata", profile: Dict, retries: int
                         logger.warning("Error downloading build logs from brew for task %s: %s", task_id, logs_err)
 
                 if error:
-                    # Looking for error message like the following to conclude the image has already been built:
-                    # BuildError: Build for openshift-enterprise-base-v3.7.0-0.117.0.0 already exists, id 588961
-                    # Note it is possible that a Brew task fails
-                    # with a build record left (https://issues.redhat.com/browse/ART-1723).
-                    # Didn't find a variable in the context to get the Brew NVR or ID.
-                    # Extracting the build ID from the error message.
-                    # Hope the error message format will not change.
-                    match = re.search(r"already exists, id (\d+)", error)
-                    if match:
-                        build_id = int(match[1])
-                        builds = brew.get_build_objects([build_id], koji_api)
-                        if builds and builds[0] and builds[0].get('state') == 1:  # State 1 means complete.
-                            build_info = builds[0]
-                            build_url = f"{BREWWEB_URL}/buildinfo?buildID={build_info['id']}"
-                            logger.info("Image %s already built against this dist-git commit (or version-release tag): %s", build_info["nvr"], build_url)
-                            error = None  # Treat as a success
+                    # Error in task does not necessarily mean error in build. Look if the build is successful
+                    build_info = koji_api.getBuild(nvr)
+                    if build_info and build_info.get('state') == 1:  # State 1 means complete.
+                        build_url = f"{BREWWEB_URL}/buildinfo?buildID={build_info['id']}"
+                        logger.info("Image %s already built against this dist-git commit (or version-release tag): %s", build_info["nvr"], build_url)
+                        error = None  # Treat as a success
 
             except Exception as err:
                 error = f"Error building image {image.name}: {str(err)}: {traceback.format_exc()}"
@@ -112,7 +103,7 @@ async def build(self, image: "image.ImageMetadata", profile: Dict, retries: int
                         "name": image.get_component_name(),
                         "version": dg.org_version,
                         "release": dg.org_release,
-                        "nvr": f"{image.get_component_name()}-{dg.org_version}-{dg.org_release}"
+                        "nvr": nvr,
                     }
                     build_url = f"{BREWWEB_URL}/buildinfo?buildID={build_info['id']}"
                 elif not build_info and not self.scratch: