`configure -C` yields different results on second run
Autoconf has a feature to cache the results of a configure run (using configure -C), and use it in subsequent runs. It greatly speeds up those subsequent runs.
- http://www.gnu.org/software/autoconf/manual/autoconf-2.66/html_node/Cache-Files.html#Cache-Files
- http://www.gnu.org/software/autoconf/manual/autoconf-2.66/html_node/Caching-Results.html
At least the FP_GCC_VERSION macro in aclocal.m4 is currently buggy. The call to AC_CACHE_CHECK should only set the cache variable (fp_cv_gcc_version), but it also sets others (GccLT34 and GccLT44) (side question: how do those interact with clang?). This means that subsequent runs of configure -C won't use the right values for GccLT34 and GccLT44, when your gcc is actually older than those.
There are likely other bugs.
Trac metadata
| Trac field | Value |
|---|---|
| Version | 7.10.2 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Build System |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | |
| Operating system | |
| Architecture |