Found the following significant warnings:
  src/rw.c:141:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:142:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:27:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:28:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:29:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:31:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:32:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:34:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:35:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:36:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:37:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:39:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:109:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:110:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:113:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:114:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:61:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:62:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:63:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:64:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:65:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:66:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:67:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:68:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:69:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:70:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:86:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:87:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:89:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:93:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
  src/rw.c:94:3: warning: ignoring return value of ‘fread’, declared with attribute warn_unused_result [-Wunused-result]
See ‘/data/gannet/ripley/R/packages/tests-devel/scs.Rcheck/00install.out’ for details.