Merge #18581: ci: Print ccache stats, add pip cache, and cleanups

73f83036298e4932772704b2d5359c78d81bd7cc ci: Add pip cache (Hennadii Stepanov)
6d480667b24dc630e7c3fe7ff032cbe1a958ab77 ci: Print ccache statistics summary (Hennadii Stepanov)
a6eea715ff549febe6d4bd52f17acb50abd99120 ci: Drop unused WINEDEBUG variable (Hennadii Stepanov)

Pull request description:

  The Travis [pip cache](https://docs.travis-ci.com/user/caching/#pip-cache) is free and saves a dozen of seconds :)

  Here are some excerpts from the Travis logs with `ccache` statistics (I found useful):

  2) [Arm64](https://travis-ci.org/github/bitcoin/bitcoin/jobs/673507749)
  ```
  ccache version 3.6
  cache directory                     /home/travis/build/bitcoin/bitcoin/ci/scratch/.ccache
  primary config                      /home/travis/build/bitcoin/bitcoin/ci/scratch/.ccache/ccache.conf
  secondary config      (readonly)    /etc/ccache.conf
  stats updated                       Fri Apr 10 18:21:06 2020
  stats zeroed                        Fri Apr 10 18:03:04 2020
  cache hit (direct)                   156
  cache hit (preprocessed)             198
  cache miss                           143
  cache hit rate                     71.23 %
  called for link                        8
  cleanups performed                     9
  files in cache                      1255
  cache size                          80.6 MB
  max cache size                     100.0 MB
  ```
  3) [s390x](https://travis-ci.org/github/bitcoin/bitcoin/jobs/673507750)
  ```
  ccache version 3.4.1
  cache directory                     /home/travis/build/bitcoin/bitcoin/ci/scratch/.ccache
  primary config                      /home/travis/build/bitcoin/bitcoin/ci/scratch/.ccache/ccache.conf
  secondary config      (readonly)    /etc/ccache.conf
  stats zero time                     Fri Apr 10 17:15:35 2020
  cache hit (direct)                   115
  cache hit (preprocessed)             163
  cache miss                            94
  cache hit rate                     74.73 %
  called for link                        6
  cleanups performed                     0
  files in cache                       804
  cache size                         304.8 MB
  max cache size                       5.0 GB
  ```
  4) [Win64](https://travis-ci.org/github/bitcoin/bitcoin/jobs/673507751)
  ```
  ccache version 3.4.1
  cache directory                     /home/travis/build/bitcoin/bitcoin/ci/scratch/.ccache
  primary config                      /home/travis/build/bitcoin/bitcoin/ci/scratch/.ccache/ccache.conf
  secondary config      (readonly)    /etc/ccache.conf
  stats zero time                     Fri Apr 10 17:38:07 2020
  cache hit (direct)                   147
  cache hit (preprocessed)             199
  cache miss                           138
  cache hit rate                     71.49 %
  called for link                        7
  cleanups performed                     7
  files in cache                      1242
  cache size                          87.0 MB
  max cache size                     100.0 MB
  ```
  5) [CentOS 7](https://travis-ci.org/github/bitcoin/bitcoin/jobs/673507752)
  ```
  ccache version 3.7.7
  cache directory                     /home/travis/build/bitcoin/bitcoin/ci/scratch/.ccache
  primary config                      /home/travis/build/bitcoin/bitcoin/ci/scratch/.ccache/ccache.conf
  secondary config      (readonly)    /etc/ccache.conf
  stats updated                       Fri Apr 10 17:45:59 2020
  stats zeroed                        Fri Apr 10 17:34:27 2020
  cache hit (direct)                   152
  cache hit (preprocessed)             200
  cache miss                           144
  cache hit rate                     70.97 %
  called for link                        8
  cleanups performed                     4
  files in cache                      1352
  cache size                          86.1 MB
  max cache size                     100.0 MB
  ```
  6) [bionic](https://travis-ci.org/github/bitcoin/bitcoin/jobs/673507753)
  ```
  ccache version 3.4.1
  cache directory                     /home/travis/build/bitcoin/bitcoin/ci/scratch/.ccache
  primary config                      /home/travis/build/bitcoin/bitcoin/ci/scratch/.ccache/ccache.conf
  secondary config      (readonly)    /etc/ccache.conf
  stats zero time                     Fri Apr 10 17:21:10 2020
  cache hit (direct)                   136
  cache hit (preprocessed)              35
  cache miss                           330
  cache hit rate                     34.13 %
  called for link                        8
  cleanups performed                    18
  files in cache                      1302
  cache size                          83.8 MB
  max cache size                     100.0 MB
  ```
  7) [xenial](https://travis-ci.org/github/bitcoin/bitcoin/jobs/673507754)
  ```
  ccache version 3.2.4
  cache directory                     /home/travis/build/bitcoin/bitcoin/ci/scratch/.ccache
  primary config                      /home/travis/build/bitcoin/bitcoin/ci/scratch/.ccache/ccache.conf
  secondary config      (readonly)    /etc/ccache.conf
  cache hit (direct)                   161
  cache hit (preprocessed)             174
  cache miss                            95
  called for link                        7
  files in cache                      3411
  cache size                           1.1 GB
  max cache size                       5.0 GB
  ```
  10) [focal](https://travis-ci.org/github/bitcoin/bitcoin/jobs/673507757)
  ```
  ccache version 3.7.7
  cache directory                     /home/travis/build/bitcoin/bitcoin/ci/scratch/.ccache
  primary config                      /home/travis/build/bitcoin/bitcoin/ci/scratch/.ccache/ccache.conf
  secondary config      (readonly)    /etc/ccache.conf
  stats updated                       Fri Apr 10 17:35:57 2020
  stats zeroed                        Fri Apr 10 17:21:32 2020
  cache hit (direct)                    78
  cache hit (preprocessed)             125
  cache miss                           107
  cache hit rate                     65.48 %
  called for link                      120
  cleanups performed                     0
  files in cache                      6218
  cache size                           1.8 GB
  max cache size                       5.0 GB
  ```
  14) [macOS 10.12](https://travis-ci.org/github/bitcoin/bitcoin/jobs/673507761)
  ```
  ccache version 3.4.1
  cache directory                     /home/travis/build/bitcoin/bitcoin/ci/scratch/.ccache
  primary config                      /home/travis/build/bitcoin/bitcoin/ci/scratch/.ccache/ccache.conf
  secondary config      (readonly)    /etc/ccache.conf
  stats zero time                     Fri Apr 10 17:47:19 2020
  cache hit (direct)                    28
  cache hit (preprocessed)               1
  cache miss                           469
  cache hit rate                      5.82 %
  called for link                        8
  cleanups performed                    17
  files in cache                      1946
  cache size                          82.6 MB
  max cache size                     100.0 MB
  ```
  15) [macOS 10.14 native](https://travis-ci.org/github/bitcoin/bitcoin/jobs/673507762)
  ```
  ccache version 3.7.8
  cache directory                     /Users/travis/build/bitcoin/bitcoin/ci/scratch/.ccache
  primary config                      /Users/travis/build/bitcoin/bitcoin/ci/scratch/.ccache/ccache.conf
  secondary config      (readonly)    /usr/local/Cellar/ccache/3.7.8/etc/ccache.conf
  stats updated                       Fri Apr 10 17:38:44 2020
  stats zeroed                        Fri Apr 10 17:22:36 2020
  cache hit (direct)                   213
  cache hit (preprocessed)             293
  cache miss                           144
  cache hit rate                     77.85 %
  called for link                       11
  called for preprocessing              56
  compile failed                        30
  preprocessor error                    56
  bad compiler arguments                14
  autoconf compile/link                 77
  no input file                         66
  cleanups performed                     0
  files in cache                      1564
  cache size                         284.6 MB
  max cache size                       5.0 GB
  ```

Top commit has no ACKs.

Tree-SHA512: f9f2c6d72680bafc7a982efc04dc37ab9bba77ffd2a4cbbc56bb0e86c5c3501d57aa2f0ebeac0113e9d8daac1ee4eac1eddf74c1172c267b37ee2d9324366c8a

0 files changed, 0 insertions, 0 deletions