Drgn does not pick up Libkdumpfile dependency during compilation

[sdimitro]

There is a problem on how compile time dependencies work in the case of drgn - specifically libkdumpfile.
I noticed this on a trunk VM from today:

delphix@sd-trunk:~$ sudo drgn
drgn 0.0.8+unknown (using Python 3.6.9, without libkdumpfile)       // <----- emphasis here
For help, type help(drgn).
>>> import drgn
>>> from drgn import NULL, Object, cast, container_of, execscript, reinterpret, sizeof
>>> from drgn.helpers.linux import *
>>>

Then looked at the actual linux-pkg job: http://ops.jenkins.delphix.com/job/devops-gate/job/master/job/linux-pkg/job/master/job/build-package/job/drgn/job/pre-push/5/console

Even though I see the dependency being installed:

19:46:46  PACKAGE drgn: STAGE fetch_dependencies STARTED
19:46:46  Running: fetch_dependencies
19:46:46  Running: mkdir /var/tmp/jenkins/workspace/devops-gate/master/linux-pkg/master/build-package/drgn/pre-push/linux-pkg/packages/drgn/tmp/dependencies
19:46:46  Running: cd /var/tmp/jenkins/workspace/devops-gate/master/linux-pkg/master/build-package/drgn/pre-push/linux-pkg/packages/drgn/tmp/dependencies
19:46:46  Fetching artifacts for dependency 'libkdumpfile' ...
19:46:46  Running: aws s3 cp --only-show-errors s3://snapshot-de-images/builds/jenkins-ops/devops-gate/master/linux-pkg/master/build-package/libkdumpfile/post-push/latest .
19:46:48  Running: cat latest
19:46:48  builds/jenkins-ops/devops-gate/master/linux-pkg/master/build-package/libkdumpfile/post-push/3Running: rm latest
19:46:48  Running: mkdir libkdumpfile
19:46:48  Running: aws s3 ls s3://snapshot-de-images/builds/jenkins-ops/devops-gate/master/linux-pkg/master/build-package/libkdumpfile/post-push/3/
19:46:48  2020-11-01 19:23:02        124 BUILD_INFO
19:46:48  2020-11-01 19:23:02         41 GIT_HASH
19:46:48  2020-11-01 19:23:02         63 PACKAGE_MIRROR_URL_MAIN
19:46:48  2020-11-01 19:23:02         61 PACKAGE_MIRROR_URL_SECONDARY
19:46:48  2020-11-01 19:23:02        579 SHA256SUMS
19:46:48  2020-11-01 19:23:02     457940 libkdumpfile-dbgsym_1.0.0-delphix-2020.10.22.04_amd64.ddeb
19:46:48  2020-11-01 19:23:02     146976 libkdumpfile_1.0.0-delphix-2020.10.22.04_amd64.deb
19:46:48  Running: aws s3 cp --only-show-errors --recursive s3://snapshot-de-images/builds/jenkins-ops/devops-gate/master/linux-pkg/master/build-package/libkdumpfile/post-push/3/ libkdumpfile/
19:46:49  Fetched artifacts for 'libkdumpfile' from s3://snapshot-de-images/builds/jenkins-ops/devops-gate/master/linux-pkg/master/build-package/libkdumpfile/post-push/3/
19:46:49  PACKAGE drgn: STAGE fetch_dependencies COMPLETED in 3 seconds
19:46:49  
19:46:49  Running: cd /var/tmp/jenkins/workspace/devops-gate/master/linux-pkg/master/build-package/drgn/pre-push/linux-pkg/packages/drgn/tmp
19:46:49  
19:46:49  PACKAGE drgn: STAGE prepare STARTED
19:46:49  Running: prepare
19:46:49  Running: install_pkgs /var/tmp/jenkins/workspace/devops-gate/master/linux-pkg/master/build-package/drgn/pre-push/linux-pkg/packages/drgn/tmp/dependencies/libkdumpfile/libkdumpfile_1.0.0-delphix-2020.10.22.04_amd64.deb
...
(Reading database ... 95%
(Reading database ... 100%
(Reading database ... 104391 files and directories currently installed.)
19:46:50  Preparing to unpack .../libsnappy1v5_1.1.7-1_amd64.deb ...
19:46:50  Unpacking libsnappy1v5:amd64 (1.1.7-1) ...
19:46:50  Selecting previously unselected package libkdumpfile.
19:46:50  Preparing to unpack .../libkdumpfile_1.0.0-delphix-2020.10.22.04_amd64.deb ...
19:46:50  Unpacking libkdumpfile (1.0.0-delphix-2020.10.22.04) ...
19:46:50  Setting up libsnappy1v5:amd64 (1.1.7-1) ...
19:46:50  Setting up libkdumpfile (1.0.0-delphix-2020.10.22.04) ...

Later when we actually configure drgn before compiling it I see:

19:47:13  checking for libkdumpfile... no

I don’t think that something is wrong with something changing in the drgn repo because the sdb nightlies have been passing (they compile both drgn and libkdumpfile from source and actively use kdumps)

Pavel tried running ./buildpkg.sh drgn in a bootstrap VM and saw the same problem. I believe it may have something to do with the libkdumpfile debian package not providing everything that drgn needs to detect that it is installed on the system during compile time (e.g. maybe the specific pkgconf/pkg-config metadata?)

[sdimitro]

Fixed for now with delphix/libkdumpfile#14