The document discusses build system maintenance. It notes that build code is complex and requires 12% of a developer's time on average. Build bugs can affect end users. Four dimensions of build maintenance are discussed: size, evolution, coupling, and people involvement. Studies found that build churn is greater than source code churn, and that build maintenance is often dispersed across many team members rather than concentrated in a small team. Tool support is needed to help with build maintenance tasks.

1. Build System Maintenance
Shane McIntosh

2. What is the build system?
.c
.c
2

3. What is the build system?
.c .c
.o .o
.exe
2

4. Build code is complex...
3

5. Build Maintenance is a
Nuisance for Developers
4

6. Build Maintenance is a
Nuisance for Developers
4

7. Build Maintenance is a
Nuisance for Developers
Make
Autotools 4

8. Build Maintenance is a
Nuisance for Developers
Make
Migration to
newer build
technology
Autotools 4

9. Build Bugs Even Affect
the End User!
5

10. Build Bugs Even Affect
the End User!
Address Bar
5

11. Build Bugs Even Affect
the End User!
Address Bar Search Bar
5

12. Build Bugs Even Affect
the End User!
Address Bar Search Bar
5

13. Build Bugs Even Affect
the End User!
Address Bar Search Bar
5

14. Build Systems Require 12%
of a Developer’s
Time (on average)
Kumfert, G., and Epperly, T.
Software in the DOE: The
Hidden Overhead of the “Build”
6

15. Build Systems Require 12%
of a Developer’s
Time (on average)
Build maintenance
slows development!
Kumfert, G., and Epperly, T.
Software in the DOE: The
Hidden Overhead of the “Build”
6

16. Four Dimensional Study of
Build Maintenance
Size Evolution Coupling People
.c ? .mk
7

17. 8

18. PLplot
8

19. Size Evolution Coupling People
.c ? .mk
9% of Build churn Tightly Dispersed or
all files >> src churn coupled concentrated
PLplot
9

20. Size Evolution Coupling People
.c ? .mk
9% of Build churn Tightly Dispersed or
all files >> src churn coupled concentrated
PLplot
10

21. Identifying build maintainers
Source
Build
.c .c .c .c .ac .c .c

22. Identifying build maintainers
Source
Build
.c .c .c .c .ac .c .c
Change Change Change Change
list #1 list #2 list #3 list #4

23. Identifying build maintainers
Source
Build
.c .c .c .c .ac .c .c
Change Change Change Change
25% build
list #1 list #2 list #3 list #4

24. Identifying build maintainers
Source
Build
.c .c .c .c .ac .c .c
Change Change Change Change
25% build
list #1 list #2 list #3 list #4

25. Identifying build maintainers
Source
Build
.c .c .c .c .ac .c .c
Change Change Change Change
25% build
list #1 list #2 list #3 list #4
0% build

26. Identifying build maintainers
Source
Build
.c .c .c .c .ac .c .c
Change Change Change Change
25% build
list #1 list #2 list #3 list #4
0% build

27. Identifying build maintainers
Source
Build
.c .c .c .c .ac .c .c
Change Change Change Change
25% build
list #1 list #2 list #3 list #4
0% build 50% build

28. Identifying build maintainers
Source
Build
.c .c .c .c .ac .c .c
Change Change Change Change
list #1 list #2 list #3 list #4
≥
0% build 50% build

29. Identifying build maintainers
Source
Build
.c .c .c .c .ac .c .c
Change Change Change Change
list #1 list #2 list #3 list #4
≥
0% build 50% build

30. If you maintain source code,
do you maintain build code?
% of developers
79%
22% 25%
12

31. If you maintain source code,
do you maintain build code?
% of developers
79%
22% 25%
12

32. Dispersed
Ownership:
Build maintenance is
distributed amongst
most team members
13

33. Dispersed
Ownership:
Build maintenance is
distributed amongst
most team members
Concentrated
Ownership:
A small team is
responsible for most
of the build maintenance
13

34. Dispersed
Ownership:
Build maintenance is
distributed amongst
most team members
Which build ownership
style performs best?
Concentrated
Ownership:
A small team is
responsible for most
of the build maintenance
13

35. Tool Support Needed
for Build Maintenance!
Build maintenance required Build churn >>
for 27% of source code tasks source churn
14

36. Size Evolution Coupling People
.c ? .mk
9% of Build churn Tightly Dispersed or
all files >> src churn coupled concentrated
PLplot
15

37. Size Evolution Coupling People
.c ? .mk
9% of Build churn Tightly Dispersed or
all files >> src churn coupled concentrated
Questions?
PLplot
15