ccache fails when switching from compiler name to a full path #1326
Description
ccache works fine when a compiler is specified by its name:
$ ccache -z && ccache env -u VAR clang -c -o main.o main.cpp && ccache -sv
Statistics zeroed
Cache directory: /home/hebasto/.cache/ccache
Config file: /home/hebasto/.config/ccache/ccache.conf
System config file: /usr/local/etc/ccache.conf
Stats updated: Fri Aug 25 12:08:19 2023
Cacheable calls: 1 / 1 (100.0%)
Hits: 0 / 1 ( 0.00%)
Direct: 0
Preprocessed: 0
Misses: 1 / 1 (100.0%)
Successful lookups:
Direct: 0 / 1 ( 0.00%)
Preprocessed: 0 / 1 ( 0.00%)
Local storage:
Cache size (GiB): 4.2 / 5.0 (83.59%)
Files: 18564
Hits: 0 / 1 ( 0.00%)
Misses: 1 / 1 (100.0%)
Reads: 2
Writes: 2
However, it fails with "Multiple source files" when the full path to the compiler is provided:
$ ccache -z && ccache env -u VAR /usr/bin/clang -c -o main.o main.cpp && ccache -sv
Statistics zeroed
Cache directory: /home/hebasto/.cache/ccache
Config file: /home/hebasto/.config/ccache/ccache.conf
System config file: /usr/local/etc/ccache.conf
Stats updated: Fri Aug 25 12:09:16 2023
Cacheable calls: 0 / 1 ( 0.00%)
Hits: 0
Direct: 0
Preprocessed: 0
Misses: 0
Uncacheable calls: 1 / 1 (100.0%)
Multiple source files: 1 / 1 (100.0%)
Successful lookups:
Direct: 0
Preprocessed: 0
Local storage:
Cache size (GiB): 4.2 / 5.0 (83.59%)
Files: 18564
Hits: 0
Misses: 0
Reads: 0
Writes: 0