Bug#1089201: debrebuild: Extra zero bytes added to .dynstr when rebuilding CMake projects

[Gioele Barabucci]

Package: devscripts
Version: 2.24.5
User: devscripts at packages.debian.org
Usertags: debrebuild
User: reproducible-builds at lists.alioth.debian.org
Usertags: toolchain
X-Debbugs-Cc: reproducible-bugs at lists.alioth.debian.org

Dear debrebuild developers,

the libraries and executables of many cmake-based packages gain extra 
zero bytes in their .dynstr ELF section when rebuilt. (This accounts for 
about 15% of the failed rebuilds.)

 From <https://reproduce.debian.net/api/v0/builds/105657/diffoscope>:

```
─ readelf --wide --decompress --hex-dump=.dynstr {}
@@ -1275,9 +1275,10 @@
    0x00009388 00474c49 42435858 5f332e34 2e323100 .GLIBCXX_3.4.21.
    0x00009398 43585841 42495f31 2e330047 4c494243 CXXABI_1.3.GLIBC
    0x000093a8 58585f33 2e342e32 3000474c 49424358 XX_3.4.20.GLIBCX
    0x000093b8 585f332e 34000000 00000000 00000000 X_3.4...........
    0x000093c8 00000000 00000000 00000000 00000000 ................
    0x000093d8 00000000 00000000 00000000 00000000 ................
    0x000093e8 00000000 00000000 00000000 00000000 ................
-  0x000093f8 00000000 0000                       ......
+  0x000093f8 00000000 00000000 00000000 00000000 ................
+  0x00009408 00000000 000000                     .......
```

Oddly, sometimes the number of zero bytes added is odd.

Regards,

-- 
Gioele Barabucci