Found while examining the shell source because of another report.

Feed a recent build of the shell with this input:

.once /tmp/valid.csv
.print 'x'
.import --csv -v -v /tmp/valid.csv '""""""""""""""""""""""""""""""""""""""""""""""'

Get this output:

Column separator ",", row separator "\n"
CREATE TABLE "main".""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""(
"x" TEXT)

Insert using: INSERT INTO """""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" VALUES)
Error: near ")": syntax error

Hint: the width of a %Q conversion is not a good predictor for the width of a %w conversion of the same value. %Q and %w have different worst case inputs.