I find myself frequently called back to the Piuparts waiting-to-be-tested package list at http://piuparts.debian.org/sid/state-dependency-failed-testing.html, and got curious about what is keeping that list as long as it is. Following is an analysis.
There are currently close to 3000 packages in state-dependency-failed-testing that can be traced to one or more state-failed-testing packages. That number actually went down quite a bit in the last week, when libgtk2.0-bin passed, clearing hundreds of packages for testing. There are less than 300 packages in state-failed-testing holding up those tests. The blocking distribution is typically very skewed. At any given time, half of the packages in state-dependency-failed-testing may be held there, directly or indirectly, by 3 to 5 packages. Eliminating libgtk2.0-bin last week exposed libreadline6 as the new top blocker. Here's the output of a script that scrapes http://piuparts.debian.org/sid/state-dependency-failed-testing.html and analyzes blocking packages: # ./piublocker dependency failed - 2899 failed testing - 274 blocking free cum package 1588 1005 1894 libreadline6 451 35 1854 sgml-data 429 1 1466 docbook-xsl 191 153 1286 texlive-base 155 79 1182 ca-certificates-java 125 106 1071 php5-cli 89 29 1042 gnustep-base-common 60 0 982 gnustep-back0.20 49 6 973 menu 49 4 957 libcommons-httpclient-java 42 0 915 python-ibus 40 15 897 libcommons-beanutils-java 35 34 862 gosa 35 1 827 blends-common 33 33 794 liquidsoap 30 3 791 libspring-core-java 28 20 771 libwebkit1.1-cil 28 1 750 libatinject-jsr330-api-java 26 26 724 drupal6 26 7 703 antlr 24 24 679 cyrus-common 21 13 664 libmx-1.0-2 20 15 645 openssh-client 17 0 630 libhttpclient-java 17 17 613 drizzle 16 16 597 dovecot-core 14 0 597 sat4j 14 6 591 proftpd-basic 14 0 577 libjasper-java 14 11 566 libhttp-date-perl 14 7 559 libgcj-bc 13 4 546 libmono-addins-gui0.2-cil 12 10 535 postfix 12 3 523 libusrp0 12 9 512 libgtkhtml-4.0-common 11 6 501 libncurses5-dev 11 6 490 libgtkglext1 ... This output says that there are currently 2899 packages in state-dependency-failed-testing traceable to a state-failed-testing package (that doesn't exactly match Piupart's count of 2920). 274 packages are responsible for that blocking. More than half of them (1588) are blocked by a single package, libreadline6. 1005 of those packages would be cleared for testing by removing only libreadline6 from the list of blockers. Possibly, at least some of those exposed packages may have blocking numbers in the 1000 range (e.g. 'python' is in that list). The "cum" shows how many packages are left as each subsequent top blocker is cleared. From that number, you can see that the dependency list could be cut in half by removing the top 4 packages on the list. 80% would be cleared by passing the top 29 packages. It seems worth the effort to identify and focus fixing the top packages on this list, over time. There should be opportunities for low-hanging fruit whenever the state-dependency-failed-testing list gets over about 1000-1500 entries. The source for the script piublocker is at https://github.com/davesteele/piublocker
